basic electronics

I - VOLTAGE AND CURRENT

1. What is the color code for a 220 5% resistor?

A. Red, Red, Brown, Gold

B. Orange, Orange, Black, Gold

C. Red, Red, Black, Gold

D. Red, Red, Brown, Silver

Answer: Option A

Explanation: Resistor colour coding series:

Black 0

Brown 1 Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Violet 7 Gray 8 White 9 None 20% Silver 10% Gold 5% Therefore Red, Red, Brown, Gold 2 2 101 5% = 22 x 10 = 220 ohm 5% (tolerance).

2. If 60 J of energy areevery 15 C of charge, what is the voltage?

A. 4 V

B. 60 V

C. 15 V

D. 0.25 V

Answer: Option A

3. An atom's atomic number is determined by the number of:

A. neutrons minus protons

B. protons

C. electrons

D. neutrons

Answer: Option B

4. A voltage will influence current only if the circuit is:

A. open

B. insulated

C. high resistance

D. closed

Answer: Option D

5. Which resistive component is designed to be temperature sensitive?

A. Thermistor

B. Rheostat

C. Potentiometer

D. Photoconductive cell

Answer: Option A

6. The battery symbol is:

A.

B.

C.

D.

Answer: Option B

7. What type of switch is this?

A. push button

B. SPST

C. DPDT

D. SPDT

Answer: Option D

8. Primary batteries, unlike secondary batteries, may be:

A. charged once

B. used once

C. recharged over and over

D. stored indefinitely

Answer: Option B

Explanation: Primary batteries (disposable batteries), which are designed to be used once and discarded when they are exhausted. Secondary batteries (rechargeable batteries), which are designed to be recharged and used multiple times.

9. In practical applications, battery

voltage:

A.

is restored as soon as

disconnect occurs

B.

is lowered as the load increases

C. may be stored indefinitely

D.

will be reduced to zero as power is drawn

Answer: Option B

10. The negative and positive charge symbols are assigned (in that order) to the:

A. proton and electron

B. electron and proton

C. atom and nucleus

D. electron and element

Answer: Option B

11. A voltmeter is used:

A. to measure current

B. in series with the circuit

C. in parallel with the circuit

D. to measure coulombs

Answer: Option C

12. If the current in a circuit equals 0 A, it is likely that the

A. voltage is too high

B. resistance is too low

C. circuit has a short

D. circuit is open

Answer: Option D

13. Current equals:

A.

B. coulombs × time

C.

D. voltage × time

Answer: Option A

14. What are the unit and symbol for current?

A. Ampere, A

B. Coulomb, I

C. Ampere, Q

D. Ampere, I

Answer: Option D

15. Which part of an atom has no electrical charge?

A. Electron

B. Neutron

C. Proton

D. All of the above

Answer: Option B

16. Which voltage source converts chemical energy to

electrical energy?

A. Electrical generator

B. Battery

C. Solar cell

D. Electronic power supply

Answer: Option B

17. An example of potential energy is:

A. tea-kettle steam

B. a moving vehicle

C. the sun

D. a battery

Answer: Option D

18. If 40 C of charge flow past a point in 20 s, what is the current?

A. 2 A B. 0.5 A

C. 20 A D. 40 A

Answer: Option A

19. Batteries differ from fuel cells in that

A. a battery is a closed system

B.

a battery uses hydrogen and oxygen to create electricity

C. a battery uses a polymer electrolyte membrane

D. none of the above

Answer: Option A

20. The removal of a non-neutral subatomic particle converts the atom into a:

A. charged ion

B. nucleus

C. heavier element

D. compound

Answer: Option A

21. One coulomb passing a point in one

second is one:

A. ampere B. volt

C. ohm D. charge

Answer: Option A

22. In which states may matter may be found?

A. solid, liquid, or mineral

B. solid, gas, or liquid

C. mineral, gas, or liquid

D. plastic, solid, or gas

Answer: Option B

23. Material that consists of a mixture of elements is considered to be:

A. an element B. an ion

C. a compound D. a molecule

Answer: Option C

24. How many valence shell electrons are

there in semiconductor atoms?

A. 16 B. 8

C. 4 D. 2

Answer: Option C

25. When considering conventional current versus electron current flow:

A. electron current flow came first

B.

protons move in conventional current flow

C.

conventional current flow came first

D.

the direction of current is the same in both methods

Answer: Option C

26. Which unit of charge contains 6.25 × 1018 electrons?

A. An ampere B. A coulomb

C. A volt D. A joule

Answer: Option B

27. A switch is a device that:

A. short circuits complex circuits

B. holds a fuse

C. has double poles

D. opens or completes a current path

Answer: Option D

28. The term used to designate electrical pressure is:

A. voltage B. current

C. resistance D. conductance

Answer: Option A

29. Which electronics material opposes the movement of free electrons?

A. Conductor B. Insulator

C. Semiconductor D. Element

Answer: Option B

30. Current is considered as the movement of:

A. electrons B. protons

C. charge D. nuclei

Answer: Option A

31. A lead-acid battery is an example of a

A. solar cell

B. fuel cell

C. primary battery

D. secondary battery

Answer: Option D

32. The charge of one coulomb is equal to:

A. 6.24 x 10−18 electrons

B. one ampere

C. one second

D. 6.24 x 1018 electrons

Answer: Option D

33. A basic electric circuit is made up of what

components?

A.

A load, a resistor, and a conductive path for current

B.

A voltage source, a load, and a conductive path for current

C.

A voltage source, a conductive path for current, and a battery

D.

A conductive path for current, a battery, and a copper wire

Answer: Option B

34. An ammeter is used to measure


C. resistance D. All of the above

Answer: Option B

35. What is the name of the pressure that moves electrons in a closed circuit?

A. amperes B. ohms

C. voltage D. coulombs

Answer: Option C

36. What is a characteristic of a secondary cell?

A. rechargeability

B. not rechargeable

C. a dry cell

D. non-liquid

Answer: Option A

37. What are the basic building blocks that all matter is composed of?

A. electrons, neutrons, and protons

B. two protons for each neutron

C. two protons for each electron

D. electrons, neutrons, and charged ions

Answer: Option A

38. If a fluid system is compared to an electrical system, the fluid pump will correspond to a:

A. conductor B. lamp

C. battery D. insulator

Answer: Option C

39. An element is a substance that is:

A. varied throughout the entire piece

B. used only in electronics

C. electrically charged

D. found only in its pure form

Answer: Option D

40. Current is:

A. the presence of a positive charge

B. the abundance of electrons

C. the movement of electrons

D. the repulsion of electrons

Answer: Option C

41. What do you call a diagram that shows the electrical connections of a circuit's components?

A. A schematic diagram

B. A pictorial diagram

C. A block diagram

D. An electrical diagram

Answer: Option A

42. A short circuit will have:

A. a small current flow

B. a large current flow

C. no current flow

D. some current flow

Answer: Option B

43. The basic difference between a fuse and a circuit breaker is

A. a fuse is slower

B. a fuse is reusable

C. a circuit breaker is reusable

D. a circuit breaker is more reliable

Answer: Option C

44. Which is the smallest?

A. atom B. proton

C. neutron D. electron

Answer: Option D

45. A secondary cell generates dc via chemical activity; a primary cell generates dc:

A. electrically B. thermally

C. optically D. chemically

Answer: Option D

46. Which of the following statements is true?

A.

Unlike charges repel and like charges attract.

B.

Like charges repel and unlike charges attract.

C.

Unlike charges attract and like charges attract.

D.

Like charges repel and unlike charges

repel.

Answer: Option B

47. If an electrical system is compared to a fluid system, the electrical current corresponds to the:

A. pressure B. pump

C. water wheel D. water flow

Answer: Option D

__________________________________________________________________________________

II - Series Circuits

1. What is the current flow through R1, R2, and R3?

A. 1A, 1A, 1A

B. 1A, 2A, 3A

C. 3A, 3A, 3A

D. 3A, 2A, 1A

Answer: Option A

Explanation:

V = IR

V = I(R1 + R2 + R3)

I = V/(R1 + R2 + R3)

= 9/(3 + 3 + 3)

= 9/9

= 1 Amp.

2. One of the most common applications of a potentiometer is as an adjustable voltage divider, also known as

A. voltage control

B. current control

C. volume control

D. divider control

Answer: Option C

3. If the resistance total in a series circuit doubles, current will:

A. be the same

B. be doubled

C. reduce source voltage

D. be halved

Answer: Option D

4. Power is defined as:

A. the rate at which work is done

B. work

C. the conversion of energy

D. joules

Answer: Option A

5. What is the dc source voltage?

A. 78 V

B. 39 V

C. 13 V

D. 0 V

Answer: Option A

6. With a total resistance of 3300 ohms and a 45 V source, if R3 is 1200 ohms, what will be its voltage drop?

A. 16.36 V

B. 32.72 V

C. 10.90 V

D. 15.00 V

Answer: Option A

7.

Calculate the voltage at point B in the given circuit.

A. +10.48 V

B. +0.94 V

C. +2.6 V

D. +3 V

Answer: Option A

8.

In the given circuit, what type of failure will cause the voltage at point B to equal the voltage at point C?

A. R1 shorts

B. R2 shorts

C. R3 shorts

D. R2 opens

Answer: Option B

9.

What is the voltage at points B to D in the given circuit?

A. +19.2 V

B. +8.8 V

C. +28 V

D. –19.2 V

Answer: Option A

10.

Calculate the voltage at point C in the given circuit.

A. +1.48 V

B. +0.94 V

C. +11.6 V

D. +3 V

Answer: Option C

11. An 8-ohm resistor is in series with a lamp. The circuit current is 1 A. With 20 V applied, what voltage is being allowed for the lamp?

A. 4 V

B. 8 V

C. 12 V

D. 20 V

Answer: Option C

12. What is wrong, if anything, with this circuit?

A. R1 is open.

B. R1 is shorted.

C. R2 is open.

D. R2 is shorted.

Answer: Option B

13. Kirchhoff’s voltage law states that:

A.

the sum of the voltage drops in a series circuit is equal to the total applied voltage

B.

the algebraic sum of the resistances is equal to the sum of the voltages

C.

the algebraic sum of the individual currents around a closed loop is zero

D.

the voltages developed across each element in a series circuit are identical

Answer: Option A

14. If series current doubles, then:

A. resistance is halved

B. voltage is doubled

C. voltage is reduced

D. resistance is doubled

Answer: Option A

15. What are the minimum and maximum output voltages?

A. 0 V, 4 V

B. 0 V, 8 V

C. 0 V, 12 V

D. 0 V, 16 V

Answer: Option D 16. A short circuit has:

A. too much resistance

B. no conductance

C. no resistance

D. low current

Answer: Option C

17. If three resistors of 1.5 kilohms, 470 ohms, and 3300 ohms are in series with a 25-volt source, what is the total circuit current?

A. 210 mA

B. 5.2 mA

C. 4.7 mA

D. .007 A

Answer: Option C

18. What is the total power in the circuit?

A. 170 mW

B. 1.7 W

C. 17 W

D. 170 W

Answer: Option A

19. A string of resistors in a series circuit will:

A.

divide the source voltage in proportion to their values

B. reduce the power to zero

C. cause the current to divide

D.

increase the source voltage in proportion to the values

Answer: Option A

20.

While putting three 1.5 V batteries into a flashlight, you put one in backwards. The flashlight will be ______________.

A. brighter than normal

B. dimmer than normal

C. off

D. the same

Answer: Option B

21.

If a voltage is connected between contacts 2 and 3 in

the given circuit, which resistors will carry current?

A. All twelve resistors will carry current.

B. Only R6 and R11 will carry current.

C. Only R2, R4, R6, and R11 will carry current.

D. Only R3, R6, R9, and R12 will carry current.

Answer: Option C

22. Given a series circuit containing resistors of different values, which statement is not true?

A. The current through each resistor is the same.

B.

The sum of the voltage drops across each resistive element will be equal.

C.

The total resistance is the sum of the value of the resistors.

D.

The voltage drop across each resistor is the

same.

Answer: Option D

23. With 20 V applied, an 8-ohm resistor is in series with a lamp. When the lamp is removed, what voltage will be read across the lamp socket?

A. 0 V

B. 8 V

C. 12 V

D. 20 V

Answer: Option D

24. When 50 V is applied to four series resistors, 100 µA

flows. If R1 = 12 k , R2 = 47 k , and R3 = 57 k ,

what is the value of R4?

A. 38.4 k

B. 3.84 k

C. 384 k

D. 3.84 M

Answer: Option C

25.

In a series circuit, the voltage measured across a short will be:

A. source voltage

B. infinite voltage

C. zero volts

D. the normal voltage drop

Answer: Option C

26.

Which is a true statement about the circuit in the given circuit?

A.

The batteries are series-aiding and the total

source voltage equals 21 V.

B.

The batteries are series-opposing and the

total source voltage equals 3 V.

C.

The batteries are series-aiding and the total source voltage equals 3 V.

D.

The batteries are series-opposing and the total source voltage equals 21 V.

Answer: Option B

27. A series circuit current:

A. remains the same through each component

B. is the same as the individual resistances

C. is subtracted by each component

D. varies through each component

Answer: Option A

28.

If R2 opens in the given circuit, what is the voltage at point B?

A. +19.2 V

B. +8.8 V

C. +28 V

D. –19.2 V

Answer: Option C

29. If 5 V and 16 V power supplies are connected in series-

opposing, what is the total voltage?

A. 11 V

B. 16 V

C. 21 V

D. 80 V

Answer: Option A

30. What is the total resistance?

A. 0 k ; there is no current

B. 2 k ; the average

C. 3 k ; the largest

D. 6 k ; the sum

Answer: Option D

31. Which equation determines individual resistor voltage

drop?

A. V x R

B. I2 x R

C. V x I

D. I x R

Answer: Option D

32. How will an open resistor affect a series circuit?

A. Current will flow around the open resistor.

B. The open resistor will drop 0 V.

C. Total resistance will decrease.

D. No current will flow in the circuit.

Answer: Option D

33. The voltage drop across a series resistor is proportional to what other value?

A. total resistance

B. its own resistance

C. wattage rating

D. the amount of time the circuit is on

Answer: Option B

34. Resistance in a series circuit will:

A. control the voltage

B. double the current

C. halve the power

D. oppose current

Answer: Option D

35.

When a battery is connected to a series circuit, it delivers current based only upon:

A. primary/secondary difference

B. total resistance

C. the polarity connections

D. average resistance

Answer: Option B

36. What determines the total resistance in a series

circuit?

A. the largest resistor

B. the sum of the resistors

C. the largest resistor minus the smaller

D. the smallest resistor

Answer: Option B

37. If two resistors have the same voltage drop in a series circuit, it means:

A. they are connected in parallel

B. they are of unequal value

C. the voltage has doubled

D. they are of equal value

Answer: Option D

38. If series resistors dissipate 16 mW, 107 mW, 146 mW, and 243 mW, what is the total power consumed by the circuit?

A. 128 mW

B. 269 mW

C. 512 mW

D. 1024 mW

Answer: Option C

39. A series circuit schematic is recognized because

all the components are connected:

A. diagonally across the page

B. in a uniform vertical manner

C. end to end in a "string"

D. horizontally across the page

Answer: Option C

40. With a 900 V source, voltage is divided across 3 series resistors of 300 V, 280 V, and:

A. 30 V

B. 270 V

C. 320 V

D. 900 V

Answer: Option C

41.

How much current flows in the circuit in the given circuit?

A. 20 A

B. 60 A

C. 80 A

D. 140 A

Answer: Option A

_______________________________________________________________________________

III - PARALLEL CIRCUITS

1. When parallel resistors are of three different values,

which has the greatest power loss?

A. The smallest resistance

B. The largest resistance

C. They have the same power loss.

D. Voltage and resistance values are needed.

Answer: Option A

2. What is the product-over-sum result of 150 and 6800?

A. 150 B. 146.7

C. 0.006 D. 6800

Answer: Option B

3. The voltage across any branch of a parallel circuit:

A. varies as the total current varies

B.

is inversely proportional to total circuit resistance

C. is equally applied to all branch conductances

D.

is dropped in proportion to each branch

resistance

Answer: Option C

4. What is the total power loss if 2 k and 1 k parallel-

connected resistors have an ITof 3 mA?

A. 6 W B. 36 W

C. 6 mW D. 36 mW

Answer: Option C

5. What happens to total resistance in a circuit with parallel resistors if one of them opens?

A. It increases. B. It halves.

C.

It remains the same.

D. It decreases.

Answer: Option A

6. Components that connect in parallel form:

A. branches B. open circuits

C. short circuits D. a voltage divider

Answer: Option A

7. A parallel circuit differs from a series circuit in that a parallel circuit has

A. no path for current flow

B. fewer paths for current flow

C. one path for current flow

D. more than one path for current flow

Answer: Option D

8.

In the given circuit, Channel 1 of the stereo amplifier outputs 12 V to the speakers. How much total current

is the amplifier providing to the speakers?

A. 0 A

B. 1.5 A

C. 3 A

D.

More information is needed to find the total current provided to the speakers.

Answer: Option C

9. If two parallel-connected resistors dissipate 6 watts and 10 watts of power, then what is the total power loss?

A. 3.75 watts B. 4 watts

C. 16 watts D. 60 watts

Answer: Option C

1

0.

Which component is shorted?

A. R1 B. R2

C. R3 D. R4

Answer: Option D

11.

What would these meter readings indicate about the circuit in the given circuit?

Meter Readings: I = 7.6 mA, V = 12 V

A. R1 is open.

B. R2 is open.

C. The fuse is open.

D. The circuit is operating normally.

Answer: Option B

12.

In the given circuit, Channel 1 of the stereo amplifier outputs 12 V to the speakers. How much total power is the amplifier delivering to the speakers?

A. 0 W

B. 18 W

C. 36 W

D.

More information is needed to find the total

power delivered to the speakers.

Answer: Option C

13. If a 1 k and a 2 k resistor are parallel-connected

across a 12 V supply, how much current is received by

the 2 k resistor?

A. 4 mA B. 6 mA

C. 8 mA D. 12 mA

Answer: Option B

1

4.

What does VS equal in the given circuit?

A. 0 V

B. 9 V

C. 27 V

D. More information is needed to find VS.

Answer: Option B

15. The current through R1 will be:

A. 128 mA B. 88 mA

C. 48 mA D. 2.2 mA

Answer: Option C

16. The voltage read by the voltmeter will be:

A. 24 V B. 12 V

C. 6 V D. 4 V

Answer: Option B

17. Which component is of the wrong value?

A. R1 B. R2

C. R3 D. R4

Answer: Option A

18.

What does I3 equal in the given circuit?

A. 5 mA B. 45 mA

C. 50 mA D. 100 mA

Answer: Option A

19. What is the total power of the circuit?

A. 2.2 W B. 4.2 W

C. 6.2 W D. 8.2 W

Answer: Option B

20. What are the individual values of two parallel resistors whose RT is 8 ohms, when one has double the resistance of the other?

A. 2.7 ohms and 5.3 ohms

B. 8 ohms and 16 ohms

C. 10 ohms and 20 ohms

D. 12 ohms and 24 ohms

Answer: Option D

21. When a parallel 5 k resistor and a 25 k resistor have a 10 V supply, what is the total

power loss?

A. 2.4 mW B. 3.3 mW

C. 24 mW D. 33 mW

Answer: Option C

22. In a parallel resistive circuit:

A.

there is more than one current path between two points

B.

the voltage applied divides between the branches

C.

the total branch power exceeds the source power

D.

the total circuit conductance is less than the smallest branch conductance

Answer: Option A

23

.

What is the total resistance?

A. 7 k B. 1 k

C. 706 D. 353

Answer: Option D

24. Kirchhoff's current law for parallel circuits states that the:

A. sum of all branch voltages equals zero

B.

total circuit resistance is less than the smallest branch resistor

C.

sum of currents into a junction is equal to the difference of all the branch currents

D.

sum of the total currents flowing out of a junction equals the sum of the total currents flowing into that junction

Answer: Option D

2 Which component is open?

5.

A. R1 B. R2

C. R3 D. R4

Answer: Option C

2

6.


Meter Readings: I = 0 mA, V = 0 V

A. R1 is open.

B. R2 is open.



Answer: Option C

27. If 550 mA of current leaves a node that had 250 mA entering from one branch, how much current would enter from the other?

A. 250 mA B. 300 mA

C. 550 mA D. 800 mA

Answer: Option B

2

8.


Meter Readings: I = 10 mA, V = 12 V

A. R1 is open.

B. R2 is open.



Answer: Option D

2

9.

What does RT equal in the given circuit?

A. 90 B. 180

C. 200 D. 1.8 k

Answer: Option A

30. What procedure should be followed when troubleshooting with an ammeter or voltmeter?

A. Short the leads and adjust.

B. Check the meter’s external power supply.

C.

Start with the highest scale and adjust down to a lower scale.

D.

Start with the lowest scale and adjust up to a higher scale.

Answer: Option C

31. A parallel circuit is also used as a divider for:

A. conductance B. voltage

C. power D. current

Answer: Option D

32. What is RT for a 12 k , a 4 k , and a 3 k resistor

in parallel?

A. 1.5 k B. 2 k

C. 6.3 k D. 19 k

Answer: Option A

33. What is the total resistance of four 1 k parallel-

connected resistors?

A. 200 ohms B. 250 ohms

C. 400 ohms D. 4 kilohms

Answer: Option B

34. Which are the better test devices used to isolate a suspected open component within a parallel circuit?

A. a voltmeter or an ohmmeter

B. neither an ammeter nor a voltmeter

C. a wattmeter or a voltmeter

D. an ammeter or an ohmmeter

Answer: Option D

3

5.

What does P2 equal in the given circuit?

A. 45 mW B. 405 mW

C. 450 mW D. 900 mW

Answer: Option B

3

6.

What does R1 equal in the given circuit?

A. 90

B. 180

C. 200

D. 1.8 k

Answer: Option B

37

.


A. 1.045 k B. 1.545 k

C. 2.045 k D. 2.545 k

Answer: Option B

38. What is RT for fifteen 2 M resistors all connected in

parallel?

A. 133 k B. 300 k

C. 750 k D. 30 M

Answer: Option A

39. Which is considered to be the common reference for a parallel circuit?

A. Voltage B. Current

C. Power D. Resistance

Answer: Option A

IV - Series-Parallel Circuits

1. What theorem replaces a complex network with an equivalent circuit containing a source voltage and a series resistance?

A. Multinetwork B. Norton

C. Thevenin D. Superposition

Answer: Option C

2.

What is the power dissipated by R2, R4, and R6?

A. P2 = 417 mW, P4 = 193 mW, P6 = 166 mW

B. P2 = 407 mW, P4 = 183 mW, P6 = 156 mW

C. P2 = 397 mW, P4 = 173 mW, P6 = 146 mW

D. P2 = 387 mW, P4 = 163 mW, P6 = 136 mW

Answer: Option A

3.

If the load in the given circit is 120 k , what is the

loaded output voltage?

A. 4.21 V

B. 15.79 V

C. 16 V

D. 19.67 V

Answer: Option B

4. In a series–parallel circuit, individual component power dissipations are calculated using:

A. individual component parameters

B. a percent of the voltage division ratio squared

C.

total current squared multiplied by the resistor values

D.

a percent of the total power depending on resistor ratios

Answer: Option A

5. The current flowing through an unloaded voltage divider is called the:

A. resistor current

B. load current

C. bleeder current

D. voltage current

Answer: Option C

6. When a Wheatstone bridge is in a balanced condition,

the center voltmeter in the bridge will read:

A. twice the source voltage

B. the same as the source voltage

C. zero volts

D. half the source voltage

Answer: Option C

7. When a load is connected to a voltage divider, the total resistance of the circuit will:

A. Decrease

B. Double

C. Increase

D. remain the same

Answer: Option A

8. With 21 V applied, if R1 = 5 ohms, R2 = 35 ohms, and R3 = 14 ohms, what is the current of R2 if R1 is series connected with parallel circuit R2 and R3?

A. 200 mA

B. 800 mA

C. 600 mA

D. 400 mA

Answer: Option D

9. What is the total resistance of a circuit when R1 (7 k )

is in series with a parallel combination of R2 (20 k ),

R3 (36 k ), and R4 (45 k )?

A. 4 k

B. 17 k

C. 41 k

D. 108 k

Answer: Option B

10.

If the load in the given circuit is 80 k , what is

the bleeder current?

A. 196 A

B. 1.96 mA

C. 2 mA

D. 2.16 mA

Answer: Option B

11

.

What is the total resistance of the given circuit?

A. 92

B. 288

C. 17.7

D. 128

Answer: Option A

12 What are the branch currents I2 and I3?

.

A. I2 = 4 mA, I3 = 2 mA

B. I2 = 4.5 mA, I3 = 2.5 mA

C. I2 = 5 mA, I3 = 3 mA

D. I2 = 5.5 mA, I3 = 3.5 mA

Answer: Option C

13

.

If the load in the given circuit is open, what is the unloaded output voltage?

A. 0 V

B. 4 V

C. 16 V

D. 20 V

Answer: Option C

1

4

.


A. 2.2 k

B. 3.2 k

C. 4.2 k

D. 5.2 k

Answer: Option B

15

.

How much voltage is dropped across R3 in the given circuit?

A. 46 V

B. 34 V

C. 23 V

D. 12 V

Answer: Option D

1

6

.

When placed into a circuit, how are electronic components usually connected?

A. positive terminal to positive terminal

B. in parallel

C. as a combination of series and parallel

D. in series

Answer: Option C

17.

If the load in the given circuit is 12 k , what is the

loaded output voltage?

A. 5.88 V

B. 14.12 V

C. 16 V

D. 17.14 V

Answer: Option B

18. If a Wheatstone bridge is balanced, a voltmeter in the center of the bridge will read:

A. the same as the source voltage

B. half the source voltage

C. zero volts

D. twice the source voltage

Answer: Option C

19. What is the voltage to the load?

A. 11.4 V

B. 12.4 V

C. 13.4 V

D. 15.4 V

Answer: Option D

20.

The first goal to accomplish in analyzing a complex series-parallel circuit is to

A. equate all parallel components

B. equate all series components

C. solve for all the voltage drops

D. solve for the total current and resistance

Answer: Option D

21

.

Which circuit fault do the meter readings in the given figure indicate?

A. The 1 k resistor is open.

B. The 4.7 k resistor is open.

C. The 2.2 k resistor is open.

D. The 3.3 k resistor is open.

Answer: Option B

22.

How much current is flowing through R1 in the given circuit?

A. 0.3 A

B. 0.15 A

C. 0.5 A

D. 0.68 A

Answer: Option C

23. If R1 is in series with parallel connected to R2 and R3, what happens to total current if R2 opens?

A. Increases

B. Decreases

C. remains the same

D. cannot tell

Answer: Option B

24. The first goal(s) to accomplish in analyzing a complex series–parallel circuit is to:

A. equate all parallel components

B. equate all series components

C. solve for all the voltage drops

D. solve for the total current and resistance

Answer: Option D

25. If a series–parallel circuit has all 30-ohm resistors, what is the total resistance when R1 is in series with a parallel circuit consisting of R2 and R3?

A. 10 ohms

B. 20 ohms

C. 45 ohms

D. 90 ohms

Answer: Option C

26.

Components or combinations of components with common currents, in a series–parallel circuit, are in:

A. parallel with each other

B. series with each other

C. either series or parallel with each other


Answer: Option C

27. What determines if resistor connections are in series, parallel, or series–parallel?

A. the voltage source

B. the power source

C. Resistance

D. current flow

Answer: Option D

28

.


A. 800

B. 1.2 k

C. 1.6 k

D. 1.8 k

Answer: Option D

29. If R1 is in series with a parallel combination of R2, R3, and R4, when the resistance value of R2 increases, the voltage across R3 will

A. Increase

B. Decrease

C. remain the same

D. Cannot tell

Answer: Option A

30A Wheatstone bridge can be used to determine an unknown

. A. Current B. resistance

C. Power D. voltage

Answer: Option B

31

.

Which circuit fault do the meter readings in the given figure indicate?

A. The 1 k resistor is shorted.

B. The 4.7 k resistor is shorted.

C. The 2.2 k resistor is shorted.

D. The 3.3 k resistor is shorted.

Answer: Option D

32. In a series–parallel circuit consisting of R1 and R2 in series and connected in parallel with R3, if R1 opens, then R2's voltage will:

A. Increase

B. Decrease

C. remain the same

D. cannot tell

Answer: Option B

33.

In the given circuit, what is RUNK equal to if RV must be

adjusted to 1,232 in order to balance the bridge?

A. 220

B. 6,899

C. 1,232

D.

More information is needed in order to find RUNK.

Answer: Option A

34. With 6 V applied, what is the voltage across R2 of a

parallel combination of R2 (1 k ), R3 (2 k ), and

R4 (1 k ) in series with R1, whose value is 2 k ?

A. 1 V

B. 3 V

C. 5 V

D. 6 V

Answer: Option A

35. What is the power dissipated by R1, R2, and R3?

A. P1 = 0.13 W, P2 = 0.26 W, P3 = 0.12 W

B. P1 = 0.26 W, P2 = 0.52 W, P3 = 0.23 W

C. P1 = 0.52 W, P2 = 0.92 W, P3 = 0.46 W

D. P1 = 1.04 W, P2 = 1.84 W, P3 = 0.92 W

Answer: Option B

V - CAPACITORS

1. In a 20 Vac series RC circuit, if 20 V is measured across the resistor and 40 V is measured across the capacitor, the applied voltage is:

A. 45 V

B. 50 V

C. 55 V

D. 60 V

Answer: Option A

2. Select the equation below that represents the relationship between charge, capacitance, and voltage for a capacitor.

A. Q = CV

B. C = QV

C.

D. V = IR

Answer: Option A

3. When is a capacitor fully charged?

A. when the voltage across its plates is of the voltage from ground to one of its plates

B.

when the current through the capacitor is the same as when the capacitor is discharged

C.

when the voltage across the plates is 0.707 of the input voltage

D.

when the current through the capacitor is directly proportional to the area of the plates

Answer: Option B

4.

What is the reactive power in the given circuit?

A. 0 VAR

B. 691 VAR

C. 44.23 mVAR

D. 1.45 kVAR

Answer: Option C

5. What is the angle theta value for a 5.6 F capacitor and

a 50-ohm resistor in series with a 1.1 kHz, 5 Vac source?

A. 27.3 degrees

B. 62.7 degrees

C. –27.3 degrees

D. –62.7 degrees

Answer: Option C

6. When a 4.7 F capacitor is connected to a 1 kHz

source, what is its capacitive reactance?

A. 4.7 ohms

B. 29.5 ohms

C. 34 ohms

D. 213 ohms

Answer: Option C

7. What is the total capacitance?

A. 1 F

B. 12 F

C. 0.615 F

D. 8 F

Answer: Option B

8. What is this circuit?

A. bandpass filter

B. high-pass filter

C. low-pass filter

D. differentiator

Answer: Option B

9. After which time constant can a capacitor be considered to be fully charged?

A. first B. third

C. fifth D. seventh

Answer: Option C

10. You could increase the time constant of an RC circuit by

A.

adding a resistor in parallel with the circuit resistance

B.

adding a capacitor in parallel with the circuit

capacitance

C. increasing the amplitude of the input voltage

D.

exchanging the position of the resistor and capacitor in the circuit

Answer: Option B

11. A capacitor's rate of charge is considered:

A. magnetic

B. a current block

C. linear

D. exponential

Answer: Option D

12. A resistor and an output capacitor form a series circuit with a square wave applied. The circuit is:

A. an integrator

B. a differentiator

C. a multiplier

D. a divider

Answer: Option A

13. If an open capacitor is checked with an ohmmeter, the needle will:

A. stay on zero

B. stay on infinity

C. move from zero to infinity

D. move from infinity to zero

Answer: Option B

14. What is the circuit's total current?

A. 4.57 mA

B. 9.327 mA

C. 11.570 mA

D. 13.830 mA

Answer: Option A

15. As a capacitor is being charged, current flowing into the capacitor will:

A. increase

B. decrease

C. remain the same

D. cannot tell

Answer: Option B

16. What is the phase shift between the voltage across the

resistor and the voltage from the source?

A. VR leads VS by 17°

B. VR leads VS by 73°

C. VR lags VS by 73°

D. VR lags VS by 17°

Answer: Option B

17. A capacitor stores energy within a dielectric between the conducting plates in the form of:

A. a magnetic field

B. positive voltage

C. negative voltage

D. an electric field

Answer: Option D

18. As a capacitor is being charged, the voltage across its terminals will:

A. increase

B. decrease

C. remain the same

D. oppose the source

Answer: Option A

19. With a 500 kHz signal source, what would be the value

of a capacitor yielding a capacitive reactance of 1 k ?

A. 318 pF

B. 2 nF

C. 3.18 F

D. 2 F

Answer: Option A

20. After a capacitor has charged for 1 tc, what percentage of current remains in the resistor?

A. 63.2 B. 36.8

C. 13.5 D. 5.0

Answer: Option B 21. If a current of 40 mA flows through a series circuit

consisting of a 0.4 F capacitor and a resistor in series

with a 4 kHz, 40 Vac source, what is the total circuit impedance?

A. 10

B. 100

C. 1 k

D. 1 M

Answer: Option C

22.

What is the capacitance of the circuit shown in the given circuit?

A. 0.066 F

B. 0.9 F

C. 65.97 pF

D. 900 pF

Answer: Option A

23. In an ac circuit, an output capacitor and a resistor are connected in series with an ac signal. What filter action will be the result?

A. bandpass B. low-pass

C. high-pass D. band-stop

Answer: Option B

24. What is the total opposition to current in a series RC circuit called?

A. impedance B. inductance

C. reactance D. resistance

Answer: Option A

25. Which of the following statements is true?

A.

The voltage to which a capacitor is charged can change instantaneously.

B.

The current in a capacitive circuit takes time

to change.

C.

A fully charged capacitor appears as a short

to dc current.

D.

An uncharged capacitor appears as a short

to an instantaneous change in current.

Answer: Option D

26. In a capacitive circuit, current flow is limited to

A. charging periods

B. discharging periods

C.

neither charging periods nor discharging

periods

D. both charging periods and discharging periods

Answer: Option D

27

.

What circuit has the following frequency response?

A. bandpass filter

B. high-pass filter

C. low-pass filter

D. integrator

Answer: Option C

28. A capacitor is constructed of two parallel:

A. conductors B. semiconductors

C. inductors D. dielectrics

Answer: Option A

29. Which of the following determines the capacitance of a capacitor?

A.

Plate area, dielectric strength, and plate

separation

B.

Voltage rating, dielectric constant, and temperature coefficient

C.

Temperature coefficient, plate area, and plate separation

D.

Plate area, dielectric constant, and plate separation

Answer: Option D

30. Most older types of paper capacitors have been replaced by which type of construction?

A. electrolytic

B. plastic film

C. oxide casing

D. waxed paper

Answer: Option B

31. If C1, a 4.7 F capacitor, and C2, a 3.3 F

capacitor are in series with 18 Vdc applied, what is the voltage across C1?

A. 3.3 V

B. 7.4 V

C. 6.6 V

D. 9.4 V

Answer: Option B

32. What is the impedance of a series RC

circuit that consists of a 0.22 F capacitor and a 200-ohm resistor connected to a 3

kHz source?

A. 214 ohms

B. 313 ohms

C. 414 ohms

D. 880 ohms

Answer: Option B

33. What is the reactance value for a capacitor installed in a dc circuit?

A. zero

B. moderate

C. infinite

D. cannot tell

Answer: Option C

34. In a purely capacitive circuit,

A. current leads voltage by 90°

B. voltage leads current by 90°

C. current lags voltage by 90°

D.

current and voltage have a phase relationship of 0°

Answer: Option A

3

5.

How long would it take the capacitor in the given circuit to completely discharge if the switch was in position 2?

A. 22 ms

B. 69 ms

C. 345 ms

D. 420 ms

Answer: Option D

36. What is the capacitive reactance if I = 1 amp, V = 2 volts, C = 5 F, and frequency = 10 Hz?

A. 0.2

B. 0.5

C. 0.02

D. 0.003

Answer: Option D

37. What is wrong with a leaky capacitor?

A. It is open.

B. It is shorted.

C. The dielectric resistance has increased.

D. The dielectric resistance has decreased.

Answer: Option D

38. What is the value of a capacitor labeled 102?

A. 10,000 pF

B. 1000 pF

C. 1000 F

D. 10,000 F

Answer: Option B

39. If the dielectric constant of a capacitor is decreased, then its capacitance will:

A. increase

B. decrease

C. remain the same

D. be destroyed

Answer: Option B

40. What is the dielectric constant for ceramic?

A. between 6 and 8000

B. 5.0

C. between 5 and 1000

D. 3000

Answer: Option A

41. What is the voltage across a capacitor after being

charged from a 100 V source for a period of one time constant?

A. 37.8 V

B. 38 V

C. 63 V

D. 101 V

Answer: Option C

42. What is the dc charging/discharging time constant for the circuit?

A. 294 ps

B. 13.5 ms

C. 21.25 ms

D. 2.16 Gs

Answer: Option C

43. Power stored from the source and then returned to the source is called:

A. apparent power

B. impedance power

C. reactive power

D. true power

Answer: Option C

44. Capacitor value markings are usually:

A. alphanumeric

B. color dabs

C. standard

D. white print

Answer: Option A

45

.

A source voltage across a capacitor will:

A. lead the current by 90 degrees

B. lead the current by 180 degrees

C. lag the current by 90 degrees

D. lag the current by 180 degrees

Answer: Option C

46

.

How long would it take the capacitor in the given circuit to completely charge if the switch was in position 1?

A. 22 ms

B. 69 ms

C. 345 ms

D. 440 ms

Answer: Option C

47. An 8 V power source is charging a capacitor. How many volts will be across the capacitor at the second time constant?

A. 1 volt

B. 3 volts

C. 5 volts

D. 7 volts

Answer: Option D

48. The material used between the plates of a capacitor is called its:

A. insulation material

B. dielectric material

C. separation material

D. plate-divider material

Answer: Option B

49. When a circuit consists of a capacitor and a resistor in series with a voltage source, and the voltage across

the resistor is zero, then the capacitor is:

A. charging

B. discharging

C. fully charged

D. fully discharged

Answer: Option C

50. Which material has the highest dielectric strength?

A. Air B. Paper

C. Mica D. Oil

Answer: Option C

51. What is the circuit's impedance?

A. 1192

B. 843

C. 723

D. 511

Answer: Option A

52. In an ac circuit, a capacitor and an output resistor are connected in series with an ac signal. What filter action will be the result?

A. bandpass B. low-pass

C. high-pass D. band-stop

Answer: Option C

53. What is the impedance of this circuit?

A. 2098

B. 2000

C. 1902

D. 1798

Answer: Option A

54. What is the reactive power?

A. 6.8 mW

B. 9.8 mW

C. 12.8 mW

D. 15.8 mW

Answer: Option B

55. A practical capacitor

A. is a short to dc

B. looks like a capacitor in parallel with a resistor

C. is an open to ac

D. stores energy in a magnetic field

Answer: Option B

56. Which of the following is the reference vector for

parallel RC circuits?

A. R B. I

C. C D. V

Answer: Option D

57. What do variable capacitors use for dielectric?

A. ceramic, electrolytic, mica, or paper

B. air, ceramic, mica, or plastic

C. ceramic, paper, plastic, or mica

D. mica, ceramic, plastic, or electrolytic

Answer: Option B

58. If a charged capacitor is disconnected from a circuit, it

will:

A. immediately discharge

B. recharge

C. remain charged

D. leak the charge

Answer: Option D

59. What is the total current for a 5 MHz, 1 Vac circuit that

consists of a 27 pF capacitor and a 1 k resistor

connected in parallel?

A. 459 A

B. 647 A

C. 1.31 mA

D. 1.85 mA

Answer: Option C

60. What is the value of a capacitor that can store two

coulombs of charge when 500 volts is applied across its plates?

A. 4 F

B. 250 F

C. 4,000 F

D. 250 F

Answer: Option C

61. The strength of an electric field at a given point is

proportional to the potential difference on the plates and inversely proportional to the:

A. plate separation

B. negative plate only

C. field strength

D. charge difference

Answer: Option A

62. How is ac current related to ac voltage in a purely capacitive circuit?

A. AC current is 0.707 of the ac voltage.

B. AC current lags ac voltage.

C. AC current is 0.637 of the ac voltage.

D. AC current leads ac voltage.

Answer: Option D

63. What is the voltage across the capacitor?

A. 7.07 V

B. 1.11 V

C. 111 mV

D. 7.07 mV

Answer: Option C

64. For a given charge difference, electrostatic field strength varies according to:

A. plate differential

B. plate area

C. plate distance

D. dielectric quantity

Answer: Option B

65. A capacitor has 25 V across its plates and a stored

charge of 1500 C. What is the capacitance value?

A. 60 pF

B. 60 F

C. 16.67 mF

D. 37.5 mF

Answer: Option B

66. A capacitor and an output resistor form a series circuit with a square wave applied. The circuit is:

A. an integrator

B. a differentiator

C. a multiplier

D. a divider

Answer: Option B

67. Capacitive reactance values connected in series offer

A. an increase in total XC

B. a decrease in total XC

C. no change in total XC

D. total opposition to voltage in the circuit

Answer: Option A

68. The quantity that represents an ideal capacitor dissipating 0 W of power is

A. instantaneous power

B. true power

C. reactive power

D. resistive power

Answer: Option B

69. If a capacitor is placed across a 20 V source, what will be the amount of charge after 5 tc?

A. 5.0 V

B. 12.8 V

C. 13.5 V

D. 20 V

Answer: Option D

70. What is the impedance of an ac RC parallel circuit if the resistance is 12 ohms and the capacitive reactance equals 5 ohms?

A. 0.2 ohms

B. 3.5 ohms

C. 4.6 ohms

D. 13 ohms

Answer: Option C

71. What will a 1 F capacitor store?

A. one coulomb of charge

B. 6.24 x 1012 electrons

C. one volt

D. one A of current

Answer: Option B

72. In an RC circuit, true power (PR) equals:

A.

B. VS × I

C. I2R

D. VT × RT

Answer: Option C

73. What is the power factor if the apparent power of a circuit is 5 W, while the true power is 4 W?

A. 0.0 W

B. 0.8 W

C. 1.0 W

D. 1.25 W

Answer: Option B

74. If the reactive power of a circuit is 50 mW while the apparent power is 64 mW, then what is the true power of the circuit?

A. 14 mW

B. 36 mW

C. 40 mW

D. 114 mW

Answer: Option C

VI – INDUCTORS

1. Electricity may be generated by a wire:

A. carrying current

B. wrapped as a coil

C. that has neutral domains

D. passing through a flux field

Answer: Option D

2.

In the given circuit, what will the voltage be

across R3 25 s after the switch is moved to position 2?

A. 2.88 V

B. 5.9 V

C. 8.34 V

D. 14 V

Answer: Option B

3. The electrical energy consumed by a coil is stored in the form of:

A. an electrical field

B. a force field

C. an electrostatic field

D. a magnetic field

Answer: Option D

4. What is magnetic flux?

A. the number of lines of force in webers

B. the number of lines of force in maxwells

C. the number of lines of force in teslas

D. the number of lines of force in flux density

Answer: Option A

5. As current travels within a conductor:

A. the magnetic field aids the current

B. a magnetic field is developed around it

C. the wire tries to point north

D. an electrostatic field opposes the current

Answer: Option B

6. What type of device consists of a coil with a moveable iron core?

A. solenoid

B. reed switch

C. relay

D. armature

Answer: Option A

7. What is hysteresis?

A. lead between cause and effect

B. lag between cause and effect

C. lead between voltage and current

D. lag between voltage and current

Answer: Option B

8. In a purely inductive circuit,

A. current leads voltage by 90°

B. voltage lags current by 90°

C. voltage leads current by 90°

D. voltage and current are in phase (0°)

Answer: Option C

9. A series RL filter circuit with an output across the inductor will result in what type of filtering?

A. passing of the higher frequencies

B. passing of the lower frequencies

C. blocking of the higher frequencies

D. blocking of a certain range of frequencies

Answer: Option A

10.

What is the total inductance in the given circuit?

A. 160 mH

B. 300 mH

C. 900 mH

D. 1700 mH

Answer: Option A

11. On a schematic, dashed lines between two vertical coils usually mean the transformer has:

A. an air core

B. an iron core

C. a nonmetallic core

D. a ferrite core

Answer: Option D

12. Faraday's law states that the:

A.

direction of the induced voltage produces an

opposition

B.

direction of an induced current produces an aiding effect

C. emf depends on the rate of cutting flux

D. emf is related to the direction of the current

Answer: Option C

13. A henry value divided by a circuit resistive value provides the:

A. counter emf value

B. induced voltage amplitude

C. rise or decay time constant

D. quality factor of the coil

Answer: Option B

14. What does Faraday's law concern?

A. a magnetic field in a coil

B. a magnetic field cutting a conductor

C. a magnetic field hystersis

D. a magnetic field in a conductor

Answer: Option B

15. The polarity of induced voltage while a field is

collapsing is:

A. independent of the force creating it

B. opposite to the force creating it

C. identical to the force creating the field

D. present only if the force is stationary

Answer: Option B

16. What is the permeability of transformer iron?

A. 50 B. 450

C. 1,500 D. 5,500

Answer: Option D

17. Electromagnetism is the:

A. magnetic field caused by a permanent magnet

B.

action between a permanent and an artificial magnet

C.

magnetic field action with a current-carrying wire

D. current in the coil

Answer: Option C

18. A magnetic field has:

A. polar fields

B. lines of force

C. magnetomotive force

D. lines of reluctance

Answer: Option B

19. Which two values are plotted on a B-H curve graph?

A. reluctance and flux density

B. permeability and reluctance

C. magnetizing force and permeability

D. flux density and magnetizing force

Answer: Option D

20. What is the number of turns required in the secondary winding for a transformer when 120 volts is applied to a 2400-turn primary to produce 7.5 Vac at the secondary?

A. 75 turns

B. 150 turns

C. 900 turns

D. 1920 turns

Answer: Option B

21. The four factors determining inductance are the number of turns, coil length, coil area, and:

A. Permeability

B. Reluctance

C. counter emf

D. coefficient of coupling

Answer: Option A

22. What is the inductive reactance if the Q of a coil is 60,

and the winding resistance is 5 ?

A. 0.083

B. 12

C. 30

D. 300

Answer: Option D

23. The time difference, or lag, between flux density and magnetizing force is known as:

A. eddy current

B. magnetic saturation

C. Hysteresis

D. Coercivity

Answer: Option C

24. A magnetic circuit breaker will open to protect equipment only when:

A. voltage is exceeded

B. an open is in the equipment

C. the equipment is operating properly

D. current is exceeded

Answer: Option D

25. Electromagnetic induction is the generation of:

A. electricity from magnetism

B. electricity from electricity

C. magnetism from electricity

D. magnetism from magnetism

Answer: Option A

26. Inductance is:

A. directly proportional to the length of the coil

B.

directly proportional to the number of turns on the coil

C.

inversely proportional to the cross-sectional area of the coil

D. inversely proportional to the permeability

Answer: Option B

27. Current will cause a magnetic field in a conductor as follows:

A.

An ac current causes a fixed polarity magnetic field.

B.

A dc current causes a fixed polarity magnetic field.

C.

A dc current causes an alternating magnetic field.

D.

An ac current causes a fixed polarity magnetic

field and a dc current causes an alternating magnetic field.

Answer: Option B

28. What is the total inductance, assuming no mutual inductance?

A. 12 mH

B. 6 mH

C. 0.73 mH

D. 0 mH

Answer: Option A

29. During a current change, the ability of a conductor to

produce counter emf within itself is called:

A. back emf

B. self-induction

C. a henry

D. impedance

Answer: Option B

30

.

If the switch is moved to position 1 in the given circuit, how long will it take for the current to reach its maximum value?

A. 72.5 s

B. 532 s

C. 610 s

D. 833 s

Answer: Option B

31. When a transformer secondary lead has been

connected to a middle loop that is not an end connector, it is called a:

A. multiple-tapped secondary

B. center-tapped secondary

C. multiple winding secondary

D. single winding secondary

Answer: Option B

32. A 24 V peak source is connected across a 900 H

inductor. If the frequency of the source is 22 kHz, what is the reactive power?

A. 2.3 VAR

B. 4.6 VAR

C. 9.3 VAR

D. 0 VAR

Answer: Option A

33. What is the permeability of machine steel?

A. 1.1 x 10−4

B. 5.65 x 10−4

C. 6.9 x 10−3

D. 8.8 x 10−3

Answer: Option B

34. What will happen when an inductor's magnetic field collapses?

A. Current will double.

B. Voltage will be induced.

C. A new field will expand.

D. Counter emf will be high.

Answer: Option B

35.

With a square wave input, an RL differentiator circuit with an output across the inductor will produce what type of waveform?

A. dc

B. short time-duration pulses

C. exponential-shaped pulses

D. only a phase shift

Answer: Option B

36. How long until the current is at a maximum?

A. 0 s

B. 5 s

C. 15 s

D. 25 s

37. Find VR and VL.

A. VR = 41.6 V, VL = 78.4 V

B. VR = 48 V, VL = 110 V

C. VR = 56 V, VL = 106 V

D. VR = 60 V, VL = 60 V

Answer: Option C

38. If 360 Vac is the output of a 300-turn secondary winding, what is the input voltage when the primary winding has 150 turns?

A. 2.4 Vac

B. 150 Vac

C. 180 Vac

D. 720 Vac

Answer: Option C

39. When a magnet enters a coil and a voltage is induced, the process is known as:

A. an alternation

B. self-inductance

C. counter emf

D. flux linkage

Answer: Option D

40. What term is used to describe the action of magnetic flux from one circuit that cuts across the conductors of another circuit?

A. self-inductance

B. rectification

C. mutual inductance

D. magnetism

Answer: Option C

41. Reactance in an inductive circuit will:

A. increase with frequency

B. decrease with frequency

C. be independent from frequency

D. depend on the value of XC

Answer: Option A

42. A turns ratio of 5 for a transformer implies:

A. more primary turns than secondary turns

B. more secondary current than primary current

C. larger source impedance than load impedance

D. more secondary turns than primary turns

Answer: Option D

43. A practical inductor

A. has inductance

B. has winding resistance

C. has winding capacitance

D. all of the above

Answer: Option D

44. When current in an inductor starts to change, it cannot react instantly due to:

A. fixed coil resistance

B. eddy current generation

C. applied emf of the circuit

D. the counter emf of the coil

Answer: Option D

45. What is the approximate time for a complete decay of

400 mA of inductor current, when R = 10 ohms and L = 20 H?

A. 10 seconds

B. 8 seconds

C. 4 seconds

D. 2 seconds

Answer: Option A

46. A utility pole transformer used to supply a residential customer with two phases uses:

A. two phases on the primary

B. a center tap on the secondary

C. a separate ground for each phase

D. a small coefficient of coupling

Answer: Option B

47. What is the inductive reactance?

A. 5.2

B. 7.5

C. 1.3 k

D. 7.5 k

Answer: Option D

48. When a coil collapses the induced circuit current will:

A. be in the same direction

B. go to zero

C. aid counter emf buildup

D. be in the opposite direction

Answer: Option A

49. When a rate of one ampere per second causes an induced voltage of one volt, the unit of measure is

A. a lenz

B. an ohm

C. a farad

D. a henry

Answer: Option D

50. If you wanted to decrease the inductance of a coil, you

might increase the:

A. number of turns

B. permeability of the core

C. spacing between turns

D. area of the coil

Answer: Option C

51. The output phase for a transformer is:

A. in phase with the input

B. out of phase with the input

C.

dependent on the direction of the primary and secondary windings

D.

dependent on the frequency of the primary

source

Answer: Option C

52. Opposition to current flow without the dissipation of energy is called:

A. resistance

B. inductive reactance

C. counter emf

D. impedance

Answer: Option B

53. With 100 Vac applied to the primary of a transformer so that it draws 500 mA, what will be the 300 Vac secondary current?

A. 1500 mA

B. 200 mA

C. 167 mA

D. 150 mA

Answer: Option C

54. Which coil would be used as a step-up transformer primary if coil number 1 has 100 more turns than coil number 2?

A. The coil windings must be the same.

B. coil 1

C. The coil ratio is too small.

D. coil 2

Answer: Option D

55. Find IR and IL.

A. IR = 50 mA, IL = 109 mA

B. IR = 150 mA, IL = 9 mA

C. IR = 50 mA, IL = 151 mA

D. IR = 150 mA, IL = 53 mA

Answer: Option D

.

56. When the transformer secondary is not loaded:

A. secondary voltage increases

B. no secondary current flows

C. no secondary voltage is present

D. secondary current increases

Answer: Option B 57. What is the current rise after 2 time

constants if Vs = 12 V dc, R = 60 , and

the inductor is rated at 24 mH?

A. 79.9 mA

B. 126.4 mA

C. 173.0 mA

D. 198.6 mA

Answer: Option C

.

58. What is the total inductance of a 5 H and a 100 mH coil connected in parallel?

A. 4.76 mH

B. 33.3 mH

C. 98.0 mH

D. 150.0 mH

Answer: Option C

.

59. A transformer is used:

A.

to couple electric energy from one dc circuit to another

B.

to couple electric energy from an ac circuit to a dc circuit

C.

to couple electric energy from a dc

circuit to an ac circuit

D.

to couple electric energy from one

ac circuit to another

Answer: Option D

.

60. Which of the following is NOT one of the three major types of fixed inductor?

A. air core

B. ferrite core

C. magnesium core

D. iron core

Answer: Option C

.

61. What is the impedance of a 1 kHz series RL circuit when R and XL are both 1000 ohms?

A. 500 ohms

B. 1000 ohms

C. 1414 ohms

D. 2000 ohms

Answer: Option C

.

62. What is remanence?

A. reactance B. reluctance

C. retentitivity D. resistance

Answer: Option C

.

63. When an electromagnet reaches maximum strength, it is considered to be:

A. in field condition

B. at saturation

C. inhibited

D. at field strength

Answer: Option B

64. You could decrease the time constant of an RL circuit by

A.

adding a resistor in parallel with the circuit resistance

B.

adding an inductor in series with the circuit inductance

C.

decreasing the amplitude of the input voltage

D.

exchanging the position of the

resistor and inductor in the circuit

Answer: Option B

.

65. Indication of transformer primary and secondary voltage relationships is accomplished by:

A. color-coded wires

B. dot notation

C. black, rather than gray, casings

D. winding ratios

Answer: Option B

.

66. As a generator armature passes the 270 degree point, the induced voltage is:

A. at maximum negative

B. between maximum negative and zero

C. at maximum positive

D. between zero and maximum positive

Answer: Option A

.

67. A value of "ten to the eighth power magnetic lines of force" is for the term:

A. field B. flux

C. coulomb D. weber

Answer: Option D

.

68. A change of one ampere per second in an inductor that induces a voltage of one volt is considered as which unit value?

A. a lenz

B. an ohm

C. a farad

D. a henry

Answer: Option D

.

69. What is the name of the part inside a relay that is moved by the action of the electromagnet?

A. armature B. conductor

C. contacts D. solenoid

Answer: Option A

.

70. If the primary of a 4:1 turns transformer dissipates 5 W, what is the secondary power?

A. 5.0 W

B. 1.25 pW

C. 9.5 W

D. 20.0 mW

Answer: Option A 71. The unit of flux density is:

A. magnetomotive force

B. a weber

C. a maxwell

D. a tesla

Answer: Option D

tesla or weber/m2 is the unit of flux density

72. When used as a filter, an inductor is

A.

placed in series with the load and aids any

current changes

B.

placed in parallel with the load and aids any

current changes

C.

placed in parallel with the load and opposes any current changes

D.

placed in series with the load and opposes any current changes

Answer: Option D

.

73. A loaded transformer will achieve mutual induction when:

A.

secondary current increase causes a primary current decrease

B.

primary current is increased by an increase in secondary current

C.

primary current is decreased by an increase in secondary current

D.

secondary current decrease causes a primary

current increase

Answer: Option B

.

74. Which transformer turns ratio is needed to match two 16-ohm parallel devices to an output of 22.2 ohms?

A. 1.38:1 B. 1.67:1

C. 0.72:1 D. 0.60:1

Answer: Option D

.

75. A transformer will have:

A. primary and secondary windings

B. primary and secondary current

C. primary wattage producing secondary current

D.

different frequencies for the primary and

secondary

Answer: Option A

.

76. What is the phase angle of a 24 Vac parallel RL circuit when R = 45 ohms and XL = 1100 ohms?

A. 0.001 degrees

B. 2.300 degrees

C. 87.600 degrees

D. 89.900 degrees

Answer: Option B

.

77. A winding of wire can be called

A. an inductor

B. a coil

C. a choke

D. All of the above

Answer: Option D 71. The unit of flux density is:


B. a weber

C. a maxwell

D. a tesla

Answer: Option D

tesla or weber/m2 is the unit of flux density

72. When used as a filter, an inductor is

A.

placed in series with the load and aids any

current changes

B.

placed in parallel with the load and aids any current changes

C.

placed in parallel with the load and opposes any current changes

D.

placed in series with the load and opposes any current changes

Answer: Option D

.

73. A loaded transformer will achieve mutual induction when:

A.

secondary current increase causes a primary current decrease

B.

primary current is increased by an increase in secondary current

C.

primary current is decreased by an increase in

secondary current

D.

secondary current decrease causes a primary

current increase

Answer: Option B

.

74. Which transformer turns ratio is needed to match two

16-ohm parallel devices to an output of 22.2 ohms?

A. 1.38:1 B. 1.67:1

C. 0.72:1 D. 0.60:1

Answer: Option D

.

75. A transformer will have:

A. primary and secondary windings

B. primary and secondary current

C. primary wattage producing secondary current

D.

different frequencies for the primary and secondary

Answer: Option A

.

76. What is the phase angle of a 24 Vac parallel RL circuit when R = 45 ohms and XL = 1100 ohms?

A. 0.001 degrees

B. 2.300 degrees

C. 87.600 degrees

D. 89.900 degrees

Answer: Option B

.

77. A winding of wire can be called

A. an inductor

B. a coil

C. a choke

D. All of the above

Answer: Option D

78. What happens when moving expanding lines of force encounter a conductor?

A. Current increases.

B. Voltage is induced.

C. Resistance is reduced.

D. Power is increased.

Answer: Option B

.

79. Fixed transformers have:

A. a center-tapped secondary

B. multiple windings

C. turns ratios that cannot be changed

D. a multiple-tapped secondary

Answer: Option C

.

80. In a B-H curve, magnetizing force is equal to:

A.

B. H = I × N

C. ampere-turns per weber

D. webers per square meter

Answer: Option A

.

81. Which of the following represents a true equivalent of

an inductor?

A.

An inductance in series with a resistance and a capacitance

B.

A capacitance in parallel with the series combination of a resistance and an inductance

C.

An inductance in parallel with the series combination of a resistance and a capacitance

D.

The only quality a real inductor has is inductance.

Answer: Option B

.

82. In a transformer, what will happen to the primary current if the secondary magnetic field increases?

A. Ip will increase.

B. Ip will be canceled.

C. Ip will remain the same.

D. Ip will decrease.

Answer: Option A

.

83. The time required for one weber of flux to cut a

conductor and produce one volt is:

A. one revolution

B. one second

C. one millisecond

D. four revolutions

Answer: Option B

.

84. What is the maximum source current for a transformer rated at 10 kVA, 1000/500 60 Hz?

A. 2 A

B. 5 A

C. 10 A

D. 20 A

Answer: Option D 85. What is the total inductance assuming no mutual

inductance?

A. 0 mH

B. 0.69 mH

C. 12 mH

D. 24 mH

Answer: Option B

.

86. A voltage is induced in a transformer secondary winding by the action of the:

A. secondary magnetic field

B. primary turns ratio

C. primary magnetic field

D. secondary counter emf

Answer: Option C

.

87. What is electromagnetism?

A.

the magnetic field generated around a conductor when a current passes through it

B.

the magnetic field generated in a conductor by an external voltage

C.

the voltage caused by a magnetic field in a conductor

D.

the current generated by an external magnetic field

Answer: Option A

.

88. Counter emf or induced voltage is:

A. inversely proportional to the change in current

B. directly proportional to the change in time

C. directly proportional to the inductance in

henrys

D.

inversely proportional to the inductance in henrys

Answer: Option C

.

89. What are the properties that determine the inductance of a coil?

A.

Length of wire, number of turns, type of core material, length of core

B.

Number of turns, type of wire, length of core,

and cross-sectional area of core

C.

Type of core material, number of turns, cross-

sectional area of core, and length of core

D.

Type of core material, type of wire, number of

turns, and cross-sectional area of core

Answer: Option C

.

90. An inductor is in series with a voltage source, an open switch, and a resistor. The instant the switch is closed, the inductor acts like

A. a short

B. an open

C. a resistor

D. a voltage source

Answer: Option B

.

91. What is the phase angle between the source voltage and current, when a 100 mH inductor with a reactance

of 6 k , and a 1 k resistor are in series with a

source?

A. 0.1 degrees

B. 9.0 degrees

C. 61.0 degrees

D. 81.0 degrees

Answer: Option D

92. When a load is not connected to the secondary of a transformer:

A. primary current is zero

B.

primary current is inversely proportional to primary impedance

C. secondary voltage is zero

D.

secondary voltage is proportional to primary

impedance

Answer: Option B

VII - RLC Circuits and Resonance

1. What is the applied voltage for a series RLC circuit when IT = 3 mA, VL = 30 V, VC = 18 V, and R = 1000 ohms?

A. 3.00 V

B. 12.37 V

C. 34.98 V

D. 48.00 V

Answer: Option B

.

2. What is the bandwidth of the circuit?

A. 31.8 Hz

B. 32.3 Hz

C. 142 Hz

D. 7.2 kHz

Answer: Option A

.

3. In a parallel RLC circuit, which value may always be used as a vector reference?

A. current B. reactance

C. resistance D. voltage

Answer: Option D

.

4. How much current will flow in a 100 Hz series RLC circuit if VS = 20 V, RT = 66 ohms, and XT = 47 ohms?

A. 1.05 A

B. 303 mA

C. 247 mA

D. 107 mA

Answer: Option C

.

5. What is the Q (Quality factor) of a series circuit that resonates at 6 kHz, has equal reactance of 4 kilo-ohms each, and a resistor value of 50 ohms?

A. 0.001 B. 50

C. 80 D. 4.0

Answer: Option C 6. What is the range between f1 and f2 of an RLC circuit

that resonates at 150 kHz and has a Q of 30?

A. 100.0 kHz to 155.0 kHz

B. 147.5 kHz to 152.5 kHz

C. 4500 kHz to 295.5 kHz

D. 149,970 Hz to 150,030 Hz

Answer: Option B

.

7. What is the quality factor?

A. 999 B. 223

C. 2.2 D. 0.99

Answer: Option C

.

8. What effect will a parallel tank have upon final filter current?

A. very little

B. The bandpass frequencies will change.

C. The frequency cutoff will change.

D. The impedance will block output.

Answer: Option A

.

9. What is the total current?

A. 56.6 mA

B. 141 mA

C. 191 mA

D. 244 mA

Answer: Option B

.

10.

When a parallel circuit resonates it is said to:

A. flywheel

B. oscillate

C. both of the above


Answer: Option C 11.

What is the resonant frequency in the given circuit?

A. 11.6 Hz

B. 275.8 Hz

C. 1.5 kHz

D. 3.2 kHz

Answer: Option D

.

12. Series RLC voltage or impedance totals must be calculated by:

A. subtracting the values

B. graphing the angles

C. adding vectors

D. multiplying the values

Answer: Option C

.

13. What is the total current?

A. 15.6 mA

B. 17.8 mA

C. 21.9 mA

D. 26.0 mA

Answer: Option A

.

14. When XC = XL the circuit:

A. draws maximum current

B. applied voltage is zero

C. is at resonance

D. draws minimum current

Answer: Option C

.

15. How much current will flow in a series RLC circuit

when VT = 100 V, XL = 160 , XC = 80 ,

and R = 60 ?

A. 1 A

B. 1 mA

C. 6.28 A

D. 10 A

Answer: Option A 16. When a full band of frequencies is allowed to

pass through a filter circuit to the output, the resonant circuit is called a:

A. low-pass filter

B. high-pass filter

C. band-stop filter

D. bandpass filter

Answer: Option D

.

17. At resonance, the term bandwidth includes all frequencies that allow what percentage of maximum current to flow?

A. 50 B. 62.3

C. 70.7 D. 95.3

Answer: Option C

.

18

.

What is the voltage across the capacitor in the given circuit?

A. 6.8 V

B. 11.9 V

C. 16.1 V

D. 22.9 V

Answer: Option D

.

1

9.

What is the impedance of the circuit in the given circuit?

A. 1.05 k

B. 1.33 k

C. 2.19 k

D. 3.39 k

Answer: Option A

.

20. In a series RLC circuit the current can be found using:

A.

B.

C. both of the above


Answer: Option C

2

1.

What is the true power consumed in a 30 V series RLC circuit if Z = 20 ohms and R = 10 ohms?

A. 15.0 watts

B. 22.5 watts

C. 30.0 watts

D. 45.0 watts

Answer: Option B

.

22. What is the current phase angle for a parallel RLC circuit when IL = 15.3 A, IC = 0.43 A, and IR = 3.5 A?

A. 76.7 degrees

B. –4.25 degrees

C. 88.8 degrees

D. –76.7 degrees

Answer: Option D

.

23. At any resonant frequency, what voltage is measured across the two series reactive components?

A. applied

B. reactive

C. zero

D. inductive and capacitive

Answer: Option C

.

24. What is the resonance frequency?

A. 31.8 Hz

B. 71 Hz

C. 7.1 kHz

D. 31.8 kHz

Answer: Option B

.

25.

What is the range between f1 and f2 of an RLC circuit that resonates at 150 kHz and has a Q of 30?

A. 100.0 kHz to 155.0 kHz

B. 147.5 kHz to 152.5 kHz

C. 4500 kHz to 295.5 kHz

D. 149,970 Hz to 150,030 Hz

Answer: Option B

26.

What is the bandwidth in the given circuit. If the

winding resistance of the coil is 12 ?

A. 6.4 kHz

B. 47.2 kHz

C. 53.7 kHz

D. 60.2 kHz

Answer: Option A

.

27. At any resonant frequency, what net voltage is measured across the two series reactive components?

A. Applied voltage

B. Reactive voltage

C. Zero voltage

D. VL + VC voltage

Answer: Option C

.

28. If the bandwidth of a filter increases:

A. Q decreases

B. the roll-off rate increases

C. the half-power frequency decreases

D. the center frequency decreases

Answer: Option A

.

29. Series RLC impedance or voltage totals must always be calculated by

A. adding values vectorially

B. graphing the angles

C. multiplying the values

D. subtracting the values

Answer: Option A

.

30

.

What is the current through the capacitor in the given circuit?

A. 3.5 mA

B. 5.5 mA

C. 9 mA

D. 11.4 mA

Answer: Option A

31

.

What is the total impedance of a 60 Hz series RLC circuit when XL = 7.5 ohms, XC = –265.3 ohms, and R = 33 ohms?

A. 257.8 ohms

B. 259.9 ohms

C. 290.8 ohms

D. 1989.75 ohms

Answer: Option B

.

32.

What is the total current for the nonideal circuit in the given circuit. If it is at resonance?

A. 0 A

B. 284 A

C. 3.3 mA

D. 38.5 mA

Answer: Option B

.

33. What is the high cutoff frequency for an RLC circuit that resonates at 2000 Hz and has a bandwidth of 250 Hz?

A. 2125 Hz

B. 2250 Hz

C. 1750 Hz

D. 8.0 Hz

Answer: Option A

.

34. Current in a series RLC circuit may always be used as:

A. a leading vector

B. a reference

C. an angle

D. a lagging vector

Answer: Option B

.

35.

What is the impedance of the circuit?

A. 12.2 k

B. 14.5 k

C. 17.8 k

D. 20.3 k

Answer: Option D 36.

What is the resonant frequency in the given circuit?

A. 6.5 kHz

B. 53.7 kHz

C. 107.4 kHz

D. 18.1 MHz

Answer: Option B

.

37.

What is the impedance of the circuit in the given circuit?

A. 125.7

B. 297.6

C. 370.1

D. 423.3

Answer: Option C

.

38. What is the approximate phase angle in a series RLC circuit when VC = 117 V, VR = 14.5 V, and VL = 3.3 V?

A. –45.0 degrees

B. –82.7 degrees

C. –90.0 degrees

D. –172.7 degrees

Answer: Option B

.

39. Which statement best describes reactance in a series RLC circuit?

A. Capacitive reactance is always dominant.

B. Inductive reactance is always dominant.

C. Resistance is always dominant.

D. The larger of the two reactances is dominant.

Answer: Option D

.

40. What is the band pass (F1 – F2) of an RLC filter that resonates at 150 kHz and has a coil Q of 30?

A. 100.0 kHz to 155.0 kHz

B. 147.5 kHz to 152.5 kHz

C. 295.5 kHz to 4500 kHz

D. 149,970 Hz to 150,030 Hz

Answer: Option B

41. What is the power factor?

A. 0.279 B. 0.479

C. 0.679 D. 0.879

Answer: Option B

.

42. What is the phase angle?

A. 61.4º B. 28.5º

C. -28.5º D. -61.4º

Answer: Option C

.

43. What would be the power factor for an RLC circuit that acts inductively?

A. +90 degrees leading

B. one

C. zero

D. –90 degrees lagging

Answer: Option C

.

44. Voltage lags current in an RLC circuit when it acts:

A. capacitively B. resistively

C. inductively D. resonantly

Answer: Option A

.

45.

What is the bandwidth of the circuit in the given circuit?

A. 11.6 Hz

B. 275.9 Hz

C. 1.5 kHz

D. 3.2 kHz

Answer: Option B What is the voltage across R1, C1, and L1?

A. VR = 156 V, VC = 165 V, VL = 441 V

B. VR = 178 V, VC = 187 V, VL = 503 V

C. VR = 219 V, VC = 232 V, VL = 619 V

D. VR = 260 V, VC = 276 V, VL = 735 V

Answer: Option A

VIII - Diodes and Applications

1. What is a varistor?

A. a voltage-dependent resistor

B. a voltage-dependent diode

C. a current-dependent resistor

D. a current-dependent diode

Answer: Option A

.

2. Which type of transformer is required to create a 180 degree input to a rectifier?

A. center-tapped secondary

B. step-down secondary

C. stepped-up secondary

D. split winding primary

Answer: Option A

.

3. What circuit activity may shift a characteristic curve so that diode operating points are different?

A. higher power (heat)

B. higher resistance

C. lower voltage

D. lower current

Answer: Option A

.

4. What is wrong with this diode?

A. open

B. short

C. nothing

D. not enough data

Answer: Option C

.

5. The dc current through each diode in a bridge rectifier equals:

A. the load current

B. half the dc load current

C. twice the dc load current

D. one-fourth the dc load current

Answer: Option A

6. When matching polarity connections have been made and the potential difference (PD) is above 0.7 V, the diode is considered to be:

A.

not

working

B.

forward

biased

C.

reverse biased

D.

an open switch

Answer: Option B

.

7. In a power supply diagram, which block indicates a smooth dc output?

A. transformer B. filter

C. rectifier D. regulator

Answer: Option D

.

8. If a 169.7 V half-wave peak has an average voltage of 54 V, what is the average of two full-wave peaks?

A. 119.9 V

B. 108.0 V

C. 115.7 V

D. 339.4 V

Answer: Option B

.

9. What is the current through the LED?

A. 0 mA

B. 23 mA

C. 18 mA

D. 13 mA

Answer: Option D

.

10. The characteristic curve for the complex model of a silicon diode shows that

A. the barrier potential is 0 V

B. the barrier potential stays fixed at 0.7 V

C.

the barrier potential increases slightly with an

increase in current

D.

the barrier potential decreases slightly with an

increase in current

Answer: Option C

11. Since diodes are destroyed by excessive current, circuits must have:

A. higher voltage sources

B. current limiting resistors

C. more dopants

D. higher current sources

Answer: Option B

.

12. A diode for which you can change the reverse bias, and

thus vary the capacitance is called a

A. varactor diode

B. tunnel diode

C. zener diode

D. switching diode

Answer: Option A

.

13. A filtered full-wave rectifier voltage has a smaller ripple than does a half-wave rectifier voltage for the same load resistance and capacitor values because:

A. there is a shorter time between peaks

B. there is a longer time between peaks

C.

the larger the ripple, the better the filtering

action


Answer: Option A

.

14. Testing a good diode with an ohmmeter should indicate

A. high resistance when forward or reverse biased

B. low resistance when forward or reverse biased

C.

high resistance when reverse biased and low resistance when forward biased

D.

high resistance when forward biased and low resistance when reverse biased

Answer: Option C

.

15. The peak inverse voltage (PIV) across a nonconducting diode in a bridge rectifier equals approximately:

A. half the peak secondary voltage

B. twice the peak secondary voltage

C. the peak value of the secondary voltage

D.

four times the peak value of the secondary voltage

Answer: Option C 16. What is the current through the diode?

A. 1 mA

B. 0.975 mA

C. 0.942 mA

D. 0.0 mA

Answer: Option A

.

17. Electrons in the outermost orbit or shell of an atom are called

A. free electrons

B. negative ions

C. valence electrons

D. conduction band electrons

Answer: Option C

.

18. Shunting the ac component away from the load is the task of a:


C. regulator D. rectifier

Answer: Option B

.

19. A pn junction allows current flow when

A.

the p-type material is more positive than the n-type material

B.

the n-type material is more positive than the p-type material

C.

both the n-type and p-type materials have the same potential

D.

there is no potential on the n-type or p-type materials

Answer: Option A

.

20. What is the current through the zener diode?

A. 0 mA

B. 7 mA

C. 8.3 mA

D. 13 mA

Answer: Option B

21. When a diode is forward biased, the voltage across it

A. is directly proportional to the current

B. is inversely proportional to the current

C. is directly proportional to the source voltage

D. remains approximately the same

Answer: Option D

.

22. Why is heat produced in a diode?

A. due to current passing through the diode

B. due to voltage across the diode

C. due to the power rating of the diode

D. due to the PN junction of the diode

Answer: Option A

.

23. The arrow in the schematic symbol of a diode points to

A. the n-type material, which is called the anode

B. the n-type material, which is called the cathode

C. the p-type material, which is called the anode

D. the p-type material, which is called the cathode

Answer: Option C

.

24. The diode schematic arrow points to the:

A. trivalent-doped material

B. positive axial lead

C. anode lead

D. cathode lead

Answer: Option D

.

25. When checking a diode, low resistance readings both ways indicate the diode is:

A. open

B. satisfactory

C. faulty

D. not the problem

Answer: Option C 26. In a diode schematic, the anode is represented by

a(n):

A. triangle

B. vertical line

C. zig-zag line

D. element indicator

Answer: Option A

.

27. An IC regulator receives an overload; it will:

A. shut down

B. compensate for heat

C. provide more voltage

D. sample and adjust

Answer: Option A

.

28. With full-wave rectification, current through the load resistor must be:

A. in opposite directions

B. to the external load

C. from the reverse biased diode

D. in the same direction

Answer: Option D

.

29. A characteristic curve is the result of a current versus voltage plot of diode activity, which begins at the:

A. 3rd quadrant

B. current plot

C. graph origin

D. voltage plot

Answer: Option C

.

30. Rectifier output polarity depends upon:

A. cycles of input

B. capacitor polarity

C. half or full wave

D. diode installation

Answer: Option D

31. With a 12 V supply, a silicon diode, and a 370-ohm resistor in series, what voltage will be dropped across the diode?

A. 0.3 V

B. 0.7 V

C. 0.9 V

D. 1.4 V

Answer: Option B

.

32. If the frequency of the applied ac signal to a half-wave rectifier is 60 Hz, the frequency of the pulsating dc output will be

A. 30 pps

B. 60 pps

C. 90 pps

D. 120 pps

Answer: Option B

.

3

3.

What is the peak output voltage for this half-wave rectifier?

A. 1 V

B. 7.8 V

C. 10.9 V

D. 15.6 V

Answer: Option B

.

34. Thermal shutdown occurs in an IC regulator if:

A. power dissipation is too high

B. internal temperature is too high

C. current through the device is too high

D. load resistance increases

Answer: Option B

.

35. The conduction band is closest to the valence band in

A. semiconductors

B. conductors

C. insulators

D.

The distance is the same for all of the above.

Answer: Option B

3

6.

What is the percent of regulation if Vnl = 20 V and Vfl = 19.8 V?

A. 0% B. 1%

C. .1% D. 5%

Answer: Option B

.

37. With a half-wave rectified voltage across the load resistor, load current flows for what part of a cycle?

A. 0 degrees

B. 90 degrees

C. 180 degrees

D. 360 degrees

Answer: Option C

.

38. Which of the following circuits would require the least amount of filtering?

A. A half-wave rectifier

B. A full-wave rectifier

C. A bridge rectifier

D. A full-wave rectifier and a bridge rectifier

Answer: Option D

.

39.

What is wrong with this circuit?

A. The zener is open.

B. The zener is shorted.

C. nothing

D. not enough data

Answer: Option A

.

40. The voltage where current may start to flow in a reverse-biased pn junction is called the

A. breakdown voltage

B. barrier potential

C. forward voltage

D. biasing voltage

Answer: Option A

41. Providing a constant output regardless of ac input or load resistance changes is the function of a:


C. regulator D. rectifier

Answer: Option C

.

42. When a diode is destroyed it has infinite impedance. When damaged by heat it will probably:

A. short

B. conduct more

C. conduct less

D. open

Answer: Option A

.

43. The area at the junction of p-type and n-type materials that has lost its majority carriers is called the

A. barrier potential

B. depletion region

C. n region

D. p region

Answer: Option B

.

44. DC power should be connected to forward bias a diode as follows:

A. – anode, + cathode

B. – cathode, – anode

C. + anode, – cathode

D. + cathode, + anode

Answer: Option C

.

45. At any given time in an intrinsic piece of semiconductor material at room temperature

A. electrons drift randomly

B. recombination occurs

C. holes are created

D. All of the above

Answer: Option D 46. In a power supply diagram, which block indicates a

pulsating dc output?


C. rectifier D. regulator

Answer: Option C

.

47. List three diode packages:

A. clip package, DIP, small current package

B.

DIP, small current package, large current

package

C.

small current package, large current package,

and SIP

D.

small current package, large current package,

clip package

Answer: Option D

.

48. The mimicking of an open/closed switch by a diode allows alternating current to be:

A. rectified B. regulated

C. controlled D. attenuated

Answer: Option A

IX - Operational Amplifiers

1. An ideal operational amplifier has

A. infinite output impedance

B. zero input impedance

C. infinite bandwidth

D. All of the above

Answer: Option C

.

2. Another name for a unity gain amplifier is:

A. difference amplifier

B. comparator

C. single ended

D. voltage follower

Answer: Option D

.

3. The open-loop voltage gain (Aol) of an op-amp is the

A.

external voltage gain the device is capable of

B.

internal voltage gain the device is

capable of

C. most controlled parameter

D. same as Acl

Answer: Option B

.

4 What is the output waveform?

.

A. sine wave

B. square wave

C. sawtooth wave

D. triangle wave

Answer: Option D

.

5. A series dissipative regulator is an example of a:

A. linear regulator

B. switching regulator

C. shunt regulator

D. dc-to-dc converter

Answer: Option A

6. What is this circuit?

A. a low-pass filter

B. a high-pass filter

C. a bandpass filter

D. a band-stop filter

Answer: Option D

.

7. A noninverting closed-loop op-amp circuit generally has a gain factor:

A. less than one

B. greater than one

C. of zero

D. equal to one

Answer: Option B

.

8. In order for an output to swing above and below a zero reference, the op-amp circuit requires:

A. a resistive feedback network

B. zero offset

C. a wide bandwidth

D. a negative and positive supply

Answer: Option D

.

9. Op-amps used as high- and low-pass filter circuits employ which configuration?

A. noninverting B. comparator

C. open-loop D. inverting

Answer: Option D

.

10.

Decreasing the gain in the given circuit could be achieved by

A. reducing the amplitude of the input voltage

B. increasing the value of the feedback resistor

C. increasing the value of the input resistor

D. removing the feedback resistor

Answer: Option C 11.

If ground is applied to the (+) terminal of an inverting op-amp, the (–) terminal will:

A. not need an input resistor

B. be virtual ground

C. have high reverse current

D. not invert the signal

Answer: Option B

.

12. An astable multivibrator is also known as a:

A. one-shot multivibrator

B. free-running multivibrator

C. bistable multivibrator

D. monostable multivibrator

Answer: Option B

.

13. With negative feedback, the returning signal:

A. aids the input signal

B. is proportional to output current

C. opposes the input signal

D. is proportional to differential voltage gain

Answer: Option C

.

14. What starts a free-running multivibrator?

A. a trigger

B. an input signal

C. an external circuit

D. nothing

Answer: Option D

.

15. A portion of the output that provides circuit stabilization is considered to be:

A. negative feedback

B. distortion

C. open-loop

D. positive feedback

Answer: Option A 16. How many leads does the TO-5 metal can package of

an operational amplifier have?

A. 8, 10, or 12

B. 6, 8, or 10

C. 8 or 14

D. 8 or 16

Answer: Option A

.

17. If a noninverting amplifier has an RIN of 1000 ohms and an RFB of 2.5 kilohms, what is the RIN voltage when 1.42 mV is applied to the correct input?

A. 3.5 mV

B. ground

C. 1.42 mV

D. 0.56 mV

Answer: Option C

.

18. Input impedance [Zin(I)] of an inverting amplifier is approximately equal to:

A. Ri

B. Rf + Ri

C. ∞

D. Rf – Ri

Answer: Option A

.

19. The closed-loop voltage gain of an inverting amplifier equals:

A.

the ratio of the input resistance to the feedback resistance

B. the open-loop voltage gain

C.

the feedback resistance divided by the input resistance

D. the input resistance

Answer: Option C

.

20

.

What is the cutoff frequency of this low-pass filter?

A. 4.8 kHz

B. 3.8 kHz

C. 2.8 kHz

D. 1.8 kHz

Answer: Option D 21

.

All of the following are basic op-amp input modes of operation EXCEPT

A. inverting mode

B. common-mode

C. double-ended

D. single-ended

Answer: Option A

.

22.What is the output voltage?

A. 15 V

B. 5 V

C. –5 V

D. –15 V

Answer: Option C

.

23. A circuit whose output is proportional to the difference between the input signals is considered to be which type of amplifier?

A. common-mode B. darlington

C. differential D. operational

Answer: Option C

.

24. With negative feedback, the returning signal

A. is proportional to the output current

B. is proportional to the differential voltage gain

C. opposes the input signal

D. aids the input signal

Answer: Option C

.

25. What is the output waveform?

A. sine wave

B. square wave

C. +15 V

D. –15 V

Answer: Option A

26. The voltage follower has a:

A.

closed-loop voltage gain of

unity

B. small open-loop voltage gain

C. closed-loop bandwidth of zero

D.

large closed-loop output impedance

Answer: Option A

.

2

7.

What is the output waveform of the circuit?

A. sine wave

B. square wave

C. sawtooth wave

D. triangle wave

Answer: Option B

.

28. The ratio between differential gain and common-mode gain is called:

A. amplitude

B. differential-mode rejection

C. common-mode rejection

D. phase

Answer: Option C

.

2

9.

What is the frequency of this 555 astable multivibrator?

A. 278 Hz

B. 178 Hz

C. 78 Hz

D. 8 Hz

Answer: Option B

.

30. If the gain of a closed-loop inverting amplifier is 3.9, with an input resistor value of 1.6 kilohms, what value of feedback resistor is necessary?

A. 6240 ohms

B. 2.4 kilohms

C. 410 ohms

D. 0.62 kilohms

Answer: Option A

31. In an open-loop op-amp circuit, whenever the inverting input (–) is negative relative to the noninverting input (+), the output will:

A. swing negative

B. close the loop

C. be balanced

D. swing positive

Answer: Option D

.

32. With a differential gain of 50,000 and a common-mode gain of 2, what is the common-mode rejection ratio?

A. –87.9 dB

B. –43.9 dB

C. 43.9 dB

D. 87.9 dB

Answer: Option D

.

33. If the input to a comparator is a sine wave, the output is a:

A. ramp voltage

B. sine wave

C.

rectangular wave

D. sawtooth wave

Answer: Option C

.

34. What three subcircuits does a phase locked loop (PLL) consist of?

A.

phase comparator, comparator, and VCO

B.

phase comparator, bandpass filter, and VCO

C.

phase comparator, bandpass filter, and demodulator

D.

phase

comparator, low-pass filter, and VCO

Answer: Option D

.

35. The major difference between ground and virtual ground is that virtual ground is only a:

A.

voltage

reference

B.

current

reference

C. power reference

D.

difference reference

Answer: Option A

3

6.

If an op-amp has one input grounded and the other input has a signal feed to it, then it is operating as what?

A. Common-mode

B. Single-ended

C. Double-ended

D. Noninverting mode

Answer: Option B

.

37. If the feedback/input resistor ratio of a feedback amplifier is 4.6 with 1.7 V applied to the noninverting input, what is the output voltage value?

A. 7.82 V

B. saturation

C. cutoff

D. 9.52 V

Answer: Option D

.

38. The Schmitt trigger is a two-state device that is used for:

A. pulse shaping

B. peak detection

C. input noise rejection

D. filtering

Answer: Option A

.

39. When a capacitor is used in place of a resistor in an op-amp network, its placement determines:

A. open- or closed-loop gain

B. integration or differentiation

C. saturation or cutoff

D. addition or subtraction

Answer: Option B

.

40.

What value of input resistance is needed in the given circuit to produce the given output voltage?

A. 50

B. 4 k

C. 4.08 k

D. 5 k

Answer: Option B

41. The common-

mode voltage gain is

A.

smaller than

differential voltage gain

B.

equal to voltage gain

C.

greater than differential voltage gain

D.

None of

the above

Answer: Option A

.

42. How many logic states does an S-R flip-flop have?

A. 2 B. 3

C. 4 D. 5

Answer: Option C

.

43.

An output that is proportional to the addition of two or more inputs is from which type of amplifier?

A.

differentiator

B.

difference

C.

summing

D

.

analog

subtractor

Answer: Option C

.

44. In a PLL, to obtain lock, the signal frequency must:

A.

come

within the lock range

B.

be less

than the capture frequency

C.

come within the capture range

D.

be greater than the capture frequency

Answer: Option C

.

45. An ideal amplifier should have:

A.

high input current

B. zero offset

C.

high output impedance

D.

moderate gain

Answer: Option B

46.

A differential amplifier has a common-mode gain of 0.2 and a common-mode rejection ratio of 3250. What would the output voltage be if the single-ended input voltage was 7 mV rms?

A. 1.4 mV rms

B. 650 mV rms

C. 4.55 V rms

D. 0.455 V rms

Answer: Option C

.

47. The magnitude of closed-loop voltage gain (Acl) of an inverting amplifier equals:

A. the ratio of the input resistance to the feedback

resistance

B. the open-loop voltage gain Aol

C.

the feedback resistance divided by the input resistance

D. the input resistance

Answer: Option C

.

48. What is the difference between common-mode and differential-mode input signals?

A. phase relationship

B. voltage

C. current

D. apparent power

Answer: Option A

.

49. A circuit that uses an amplifier with passive filter elements is called a(n):

A. relaxation oscillator

B. signal generator

C. differential amplifier

D. active filter

Answer: Option D

.

50. The input offset current equals the

A. average of two base currents

B. collector current divided by the current gain

C. difference between two base-emitter voltages

D. difference between two base currents

Answer: Option D

X - QUANTITIES AND UNITS

1. Derived units are obtained from various combinations of

A. electrical quantities

B. fundamental units

C. metric prefixes

D. international standards

Answer: Option B

.

2. Which of the following metric prefixes could replace 10–9?

A. Nano B. Mega

C. Kilo D. Micro

Answer: Option A

.

3. Scientific notation is a method

A. of expressing a very large number

B. of expressing a very small number

C. used to make calculations with large and small numbers

D. All of the above

Answer: Option D

.

4. If you drop a 5 when rounding a number, you are using the

A. round-to-even rule

B. significant digit rule

C. round-off rule

D. retained digit rule

Answer: Option A

.

5. 7200 mV is the same as

A. 7.2 V

B. 7.2 V

C. 7,200,000 V

D. 0.0072 V

Answer: Option B

6. A measure of the repeatability of a measurement of some quantity is

A. error B. precision

C. accuracy D. significant

Answer: Option B

.

7. Another name for "fundamental units" is

A. base units

B. atoms

C. the metric system

D. letter symbols

Answer: Option A

.

8. Adding 27.5 × 103 to 8.9 × 104 equals

A. 36.4 × 107

B. 116.5 × 104

C. 28.39 × 103

D. 1.165 × 105

Answer: Option D

.

9. When using the terms "accuracy" and "precision" for measurements

A. "precision" implies less measurement error than "accuracy"

B. "accuracy" implies less measurement error than "precision"

C. "precision" measures the repeatability of a measurement

D. both terms mean the same thing

Answer: Option C

.

10. The difference between scientific and engineering notation is

A. powers of ten representation

B. single vs. multiple digits before decimal point

C. groupings of multiples of three digits

D. All of the above

Answer: Option D

11. The number 14.8 can also be expressed as

A. 1.48 × 10–1

B. 1.48 × 100

C. 1.48 × 101

D. 1.48 × 102

Answer: Option C

.

12. The digits in a measured number that are known to be correct are called

A. accuracy digits

B. significant digits

C. error digits

D. precision digits

Answer: Option B

.

13. Which of the following is expressed in engineering notation?

A. 470 × 105

B. 82 × 10–2

C. 9.1 × 10–6

D. 14.7 × 108

Answer: Option C

.

14. The unit for frequency is the

A. hertz B. ampere

C. watt D. second

Answer: Option A

.

15. Add 21 mA and 8000 A and express the result in milliamperes.

A. 21.8 mA

B. 218 mA

C. 29 mA

D. 290 mA

Answer: Option C

16. Dividing 24 × 1011 by 3 × 104 equals

A. 8 × 104

B. 8 × 107

C. 8 × 1011

D. 8 × 1015

Answer: Option B

.

17. Pico is what relation to micro?

A. one-tenth B. one-hundredth

C. one-thousandth D. one-millionth

Answer: Option D

XI - Ohm's Law

1. "Half-splitting" is

A.

a means for nuclear fuel cells to produce

electricity

B. a means of isolating a problem in a circuit

C.

a means for reducing a high ac voltage to a low dc voltage

D. a means of limiting current in a circuit

Answer: Option B

.

2. If doubling the voltage across a resistor doubles the current through the resistor then

A. the resistor value decreased

B. the resistor value did not change

C. the resistor value increased

D.

it is impossible to determine the change in the

resistor value

Answer: Option B

.

3. If the voltage across a fixed value of resistance is increased five times, what does the current do?

A. It increases by a factor of five.

B. It decreases by a factor of five.

C. It stays the same.

D. Not enough information

Answer: Option A

.

4. If the resistance in a circuit with constant voltage increases, the current will

A. increase

B. decrease

C. stay the same

D. Not enough information

Answer: Option B

.

5.

What is the power in the given circuit?

A. 3.6 W

B. 35 W

C. 175 W

D. 245 W

Answer: Option B 6. What is the kilowatt-hour consumption

of a 40 W lamp if it remains on for 1750 h?

A. 43.75 B. 70

C. 43,750 D. 70,000

Answer: Option B

(1,750 x 40)/1000 = 70 kilowatt-hour.

7. A damaged resistor

A. may appear burned

B.

may have an increased resistance value

C.

may be checked with an ohmmeter

D. All of the above

Answer: Option D

.

8. Power supplies differ from batteries in that

A.

power supply output voltages are ac and not dc

B.

power supply voltages are not stable

C.

power supplies are low-current

devices

D. None of the above

Answer: Option D

.

9.

What is the resistor value in the given circuit?

A. 200

B. 1 k

C. 2 k

D. 4 k

Answer: Option C

.

10. If voltage across a resistance doubles

A. the current is halved

B. the resistance doubles

C. the current is unchanged


Answer: Option D

11

.


A. 32 W

B. 80 W

C. 500 W

D. 16 kW

Answer: Option A

.

12. Ohm's law describes the mathematical relationship between

A. ohms, kilohms, and megohms

B. resistor size and resistor value

C. resistance, voltage, and current


Answer: Option C

.

13. Energy is defined as the ability to

A. produce heat

B. produce light

C. produce sound

D. All of the above

Answer: Option D

.

14. What electromotive force would cause 20 A of current

to flow through a 500 resistor?

A. 0.04 V

B. 2.5 V

C. 25.0 V

D. 10,000 V

Answer: Option D

.

15. The rate at which work is performed is called

A. current B. energy

C. power D. voltage

Answer: Option C 16. A battery's capacity to deliver power is measured in

A. kWh B. Ah

C. Wh D. Vh

Answer: Option B

.

17. Power supplies are regulated to prevent the output voltage from changing due to changes in the

A. line voltage

B. supply load

C. frequency

D. both line voltage and supply load

Answer: Option D

.

18.


A. 3.92 kW

B. 280 W

C. 28.6 W

D. 9.8 W

Answer: Option D

.

19. If current through a resistance is halved

A. the resistance is halved

B. the voltage is halved

C. the voltage doubles


Answer: Option B

.

20. Ohm's law is a relationship between

A. voltage, current, and time

B. power, current, and resistance

C. resistance, time, and current

D. voltage, current, and resistance

Answer: Option D

If the voltage in the given circuit was cut in half, what

would the current equal?

A. 10 mA

B. 30 mA

C. 60 mA

D. 90 mA

Answer: Option B

XI - MAGNETISM AND ELECTROMAGNETISM

1. Permeability is the inverse equivalent of which electrical term?

A. Voltage B. Current

C. Resistance D. Conductance

Answer: Option C

.

2. Which electromagnetic device uses brushes and a commutator?

A. A speaker

B. A dc generator

C. A relay

D. A solenoid

Answer: Option B

.

3. What is the flux density of a magnetic field whose flux is 3000 µWb and cross-sectional area is 0.25 m2?

A. 12,000 T

B. 83,330 T

C. 0 T

D.

More information is needed in order to find flux

density.

Answer: Option A

.

4. How much flux is there in a magnetic field when its flux

density is 5000 T and its cross-sectional area is 300 mm2?

A. 16.67 mWb

B. 5.0 Wb

C. 3.0 mWb

D. 1.5 Wb

Answer: Option D

.

5. What are the effects of moving a closed wire loop through a magnetic field?

A. A voltage is induced in the wire.

B. A current is induced in the wire.

C.

The polarity across the wire

depends on the direction of motion.

D. All of the above

Answer: Option D 6. The Hall effect

A.

is a phenomenon with no practical applications

B.

is used in various sensor applications

C.

can develop potentials of thousands of volts

D. is the basis for solar cell

operation

Answer: Option B

.

7. "Series" and "parallel" as applied to dc motors refer to

A.

the connection of the motor and controller

B.

the connection of the field coil and armature windings

C.

the connection of the brush and

commutator

D.

the connection of the motor

batteries

Answer: Option B

.

8. The component that produces power in an electromagnetic generator is called the

A. armature

B. field winding

C. commutator

D. brush

Answer: Option A

.

9. What is the magnetomotive force in a 150-turn coil of wire with 2 A flowing through it?

A. 13.33 mAt

B. 300 At

C. 75 At

D. 152 At

Answer: Option B

.

10. A Hall effect sensor

A. exists only in theory

B.

is a noncontacting magnetic sensor

C.

can operate only a few times before failure

D. produces very large voltages

Answer: Option B

11. Which two values are plotted on a B-H curve graph?

A. Reluctance and flux density

B. Permeability and reluctance

C.

Magnetizing force and permeability

D.

Flux density and magnetizing force

Answer: Option D

.

12. Which electromagnetic device has a flexible cone?

A. A speaker

B. A dc generator

C. A relay

D. A solenoid

Answer: Option A

.

13. What is the reluctance of a material that has a length of 0.045 m, a cross-sectional area of 0.015 m2, and a permeability of 2500 µWb/At·m?

A. 833.33 µAt/Wb

B. 0.27 At/Wb

C. 1200 At/Wb

D.

More information is needed in order to find the reluctance.

Answer: Option C

.

14. The unit of flux density is known as


B. a weber

C. a maxwell

D. a tesla

Answer: Option D

.

15. What do you call the characteristic of a magnetic material whereby a change in magnetization lags the application of a magnetizing force?

A. Hysteresis B. Induction

C. Retentivity D. Reluctance

Answer: Option A 11. Which two values are plotted on a B-H curve graph?

A. Reluctance and flux density

B. Permeability and reluctance

C. Magnetizing force and permeability

D. Flux density and magnetizing force

Answer: Option D

.

12. Which electromagnetic device has a flexible cone?

A. A speaker

B. A dc generator

C. A relay

D. A solenoid

Answer: Option A

.

13. What is the reluctance of a material that has a length of 0.045 m, a cross-sectional area of 0.015 m2, and a permeability of 2500 µWb/At·m?

A. 833.33 µAt/Wb

B. 0.27 At/Wb

C. 1200 At/Wb

D.

More information is needed in order to find the

reluctance.

Answer: Option C

.

14. The unit of flux density is known as


B. a weber

C. a maxwell

D. a tesla

Answer: Option D

.

15. What do you call the characteristic of a magnetic material whereby a change in magnetization lags the

application of a magnetizing force?

A. Hysteresis B. Induction

C. Retentivity D. Reluctance

Answer: Option A 16. Which electromagnetic device has a movable iron core

called a plunger?

A. A speaker

B. A dc generator

C. A relay

D. A solenoid

Answer: Option D

.

17. Which electromagnetic device contains an armature?

A. A speaker

B. A dc generator

C. A relay

D. A solenoid

Answer: Option B

.

18. The polarity of induced voltage while a field is collapsing is

A. independent of the force creating the field

B. opposite to the force creating the field

C. identical to the force creating the field

D. present only if the force is stationary

Answer: Option B

XIII - Alternating Current and Voltage

1.

What type of waveform is shown in the given circuit?

A. Sine wave

B. Square wave

C. Triangle wave

D. Sawtooth wave

Answer: Option C

.

2. In both induction and synchronous ac motors

A. the operating speed is very steady

B. the stator magnetic field is stationary

C. the stator magnetic field rotates

D. the "squirrel cage" forms the rotor

Answer: Option C

.

3.

What is the peak-to-peak voltage of the waveform in the given circuit?

A. 2 V

B. 4 V

C. 6 V

D. 8 V

Answer: Option D

.

4. Most practical alternators generate electricity from

A. a coil rotating within a magnetic field

B. a magnetic field rotating around fixed windings

C.

a permanent magnet rotating within a varying

electromagnetic field


Answer: Option B

.

5. A half-cycle average voltage of 12 V is equal to what rms voltage?

A. 13.33 V

B. 8.48 V

C. 18.84 V

D. 7.64 V

Answer: Option A

6. What is the instantaneous peak voltage at 250° on a 6 V peak sine wave?

A. +5.64 V

B. –5.64 V

C. +26.13 V

D. –26.13 V

Answer: Option B

.

7.

Calculate the positive-going slope of the waveform in

the given circuit.

A. 5 V/ms

B. 2.5 V/ms

C. 2.5 V/s

D. 5 V/s

Answer: Option B

.

8. A rectangular wave that has a duty cycle of 50% could be called a

A. "c" wave

B. sawtooth wave

C. square wave

D. triangular wave

Answer: Option C

.

9.

Calculate the duty cycle of the repetitive pulse waveform in the given circuit.

A. 8.33% B. 0%

C. 33.33% D. 25%

Answer: Option D

.

10. The effective value of a sine wave is equal to

A. 0.707 of peak voltage

B. 0.636 of peak voltage

C. sin 45° of peak voltage

D.

both 0.707 of peak voltage and sin 45° of peak voltage


What is the dc voltage of the waveform in the given circuit?

A. 2 V

B. 4 V

C. 6 V

D. 8 V

Answer: Option C

.

12. What is the fourth harmonic of a fundamental frequency of 400 Hz?

A. 100 Hz

B. 4 kHz

C. 4 Hz

D. 1.6 kHz

Answer: Option D

.

13.

What is the peak voltage across R3 in the given

circuit?

A. 1.2 V

B. 5 V

C. 7 V

D. 12 V

Answer: Option B

.

14

.

Which point is the trailing edge of the repetitive pulse waveform in the given circuit?

A. Point A

B. Point B

C. Point C

D. Point D

Answer: Option A

.

15. A single-phase induction motor

A. is self-starting

B. operates at a fixed speed

C.

is less reliable than a three-phase

synchronous motor


Answer: Option D

1

6

.

What is the average voltage when a rectangular wave's base line voltage is 20 V, its peak-to-peak voltage is 50 V, and its duty cycle is 20%?

A. 26 V

B. 30 V

C. 40 V

D. 45 V

Answer: Option B

XIV - RC Circuits

1. In a 20 Vac series RC circuit, if 20 V is read across the resistor and 40 V is measured across the capacitor, the applied voltage is

A. 45 Vac

B. 50 Vac

C. 60 Vac

D. 65 Vac

Answer: Option A

.

2. Which of the following is the reference vector for parallel RC circuits?

A. R B. V

C. I D. XC

Answer: Option B

.

3.

What is the voltage drop across R1 in the given circuit?

A. 10 V

B. 4.80 V

C. 4.00 V

D. 5.80 V

Answer: Option D

.

4. Power that is measured in volt-amperes is called

A. impedance power

B. reactive power

C. true power

D. apparent power

Answer: Option D

.

5. As frequency increases

A. both series and parallel RC impedance decrease

B.

series RC impedance decreases and parallel RC impedance increases

C.

series RC impedance increases and

parallel RC impedance decreases

D. both series and parallel RC impedance increase

Answer: Option A

6.

Calculate the magnitude of the impedance in the given circuit.

A. 24.1 M

B. 10 M

C. 26.1 M

D. 0

Answer: Option C

.

7.

Calculate the phase angle in the given circuit.

A. 0° B. 90°

C. 22.52° D. 67.48°

Answer: Option D

.

8. What is the phase angle for a parallel circuit consisting of a 500 kHz, 5 Vac source with a 47 pF capacitor, and a

4.7 k resistor in parallel?

A. 55.3° B. –55.3°

C. 34.8° D. –34.8°

Answer: Option C

.

9.

Which circuit is represented by the frequency response curve in the given figure?

A. High-pass filter

B. Low-pass filter

C. Band-pass filter

D.

Band-stop filter

Answer: Option B

.

10

.

What is the phase angle in the given circuit?

A. 14.95° B. 36.88°

C. 0° D. 90°

Answer: Option A

11

.

What is the current through XC1 in the given circuit?

A. 32.2 mA

B. 16 mA

C. 12 mA

D. 48 mA

Answer: Option A

.

12.

What is the total current in the given circuit?

A. 0.28 A

B. 0.399 A

C. 909 A

D. 0.2 A

Answer: Option A

.

13. Which statement about a series RC circuit is true?

A.

The capacitor's voltage drop is in phase with the resistor's voltage drop.

B. The current leads the source voltage.

C. The current lags the source voltage.

D. The resistor voltage lags the current.

Answer: Option B

.

14.

If the frequency increases in the given circuit, how would the total current change?

A. The total current would increase.

B. The total current would decrease.

C. The total current would remain the same.

D.

More information is needed in order to predict

how the total current would change.

Answer: Option A

.

15. What is the effect of increasing the resistance in a series RC circuit?

A. There will be no effect at all.

B. The current will increase.

C. The phase shift will decrease.

D. The input voltage will increase.

Answer: Option C

RL Circuits

1. As frequency increases

A. both series and parallel RL impedance decrease

B.

series RL impedance decreases and

parallel RL impedance increases

C.

series RL impedance increases and parallel RL impedance decreases

D. both series and parallel RL impedance increase

Answer: Option D

.

2.

Calculate the voltage dropped across R1 in the given circuit.

A. 14 V

B. 26.8 V

C. 28 V

D. 0 V

Answer: Option B

.

3. What is the true power of a 24 Vac parallel RL circuit

when R = 45 and XL = 1100 ?

A. 313.45 W

B. 12.8 W

C. 44.96 W

D. 22.3 W

Answer: Option B

.

4. If XL= 100 and R = 100 , then impedance will be

A. 141.4

B. 14.14

C. 100

D. 200

Answer: Option A

.

5.

Which of the following statements is true if the inductor shorts out in the circuit in the given circuit?

A. Each component drops 5 V.

B. The impedance equals 0 .

C. The power factor equals 1.

D. The phase angle equals 90°.

Answer: Option C 6.

Calculate the voltage dropped across L2 in the given circuit.

A. 18 V

B. 6 V

C. 13.5 V

D. 0 V

Answer: Option B

.

7. What is the magnitude of the phase angle of a 24 Vac

parallel RL circuit when R = 45 and XL = 1100 ?

A. 0.001° B. 2.3°

C. 87.6° D. 89.9°

Answer: Option B

.

8.

Which of the following statements is true if the frequency decreases in the circuit in the given circuit?

A. The phase angle decreases.

B. VR decreases.

C. IT decreases.

D. VS decreases.

Answer: Option A

.

9. What is the magnitude of the phase angle between the source voltage and current when a 100 mH inductor

with an inductive reactance of 6 k and a 1 k

resistor are in series with a source?

A. 0.1° B. 9.0°

C. 61.0° D. 81.0°

Answer: Option D

.

10.

Which of the following statements is true if R1 opens in the circuit in the given circuit?

A. IL2 increases.

B. ZT decreases.

C. VS increases.

D. VL1 equals 0 V.

Answer: Option D

11.

Which of the following statements is true if R = 100

and XL = 100 in the circuit in the given circuit?

A. Each component drops 5 V.

B. The impedance equals 200 .

C. The power factor equals 1.

D. The phase angle equals 45°.

Answer: Option D

.

1

2

.

Which of the following statements is true about a lag network?

A.

An increase in frequency causes an increase in

phase lag.

B.

An increase in frequency causes an increase in the magnitude of the output voltage.

C.

A decrease in frequency causes an increase in phase lag.

D.

A decrease in frequency causes a decrease in the magnitude of the output voltage.

Answer: Option A

XVI - TRANSFORMERS

1. When does maximum power transfer happen from the source to the load?

A.

When the source resistance is greater than the load resistance

B.

When the source resistance is less than the

load resistance

C. When there is negligible source resistance

D.

When the source resistance equals the load resistance

Answer: Option D

.

2. A transformer is plugged into a 120 V rms source and has a primary current of 300 mA rms. The secondary

is providing 18 V across a 10 load. What is the

efficiency of the transformer?

A. 88% B. 90%

C. 92% D. 95%

Answer: Option B

.

3. The coefficient of coupling between two coils is 0.45. The first coil has an inductance of 75 mH and the

second coil has an inductance of 105 mH. What is the mutual inductance between the coils?

A. 3.54 mH

B. 7.88 mH

C. 39.9 mH

D. 189.3 mH

Answer: Option C

.

4. Increasing the number of turns of wire on the secondary of a transformer will

A. increase the secondary current

B. decrease the secondary current

C. have no effect on the secondary current

D. increase the primary current

Answer: Option B

.

5. What is the turns ratio of the transformer needed to

match a 1 k source resistance to a 160 load?

A. 2.5:1 B. 0.4:1

C. 6.25:1 D. 16:1

Answer: Option B 6.

What is the secondary voltage in the given circuit?

A. 13.3 V rms in phase with the primary

B. 120 V rms in phase with the primary

C. 13.3 V rms out of phase with the primary

D. 120 V rms out of phase with the primary

Answer: Option C

.

7. The transformer turns ratio determines

A. the ratio of primary and secondary voltages

B. the ratio of primary and secondary currents

C. the reflected impedance

D. all of the above

Answer: Option D

.

8. Mutual induction is dependent on

A. winding ratios

B. output polarities

C. dc voltage levels

D. current changes

Answer: Option D

.

9.

What is the current through the load in the given circuit?

A. 500 A

B. 10 mA

C. 250 mA

D. 1.25 A

Answer: Option C

.

10.

What is the power dissipated in the primary of the transformer in the given circuit?

A. 25 mW

B. 500 mW

C. 12.5 W

D. 62.5 W


A special transformer used to convert unbalanced signals to balanced signals is the

A. balun

B. autotransformer

C. center-tapped transformer

D. step-across transformer

Answer: Option A

.

12.

If the load doubled in value in the given circuit, what reflected resistance would the source see?

A. 80

B. 400

C. 2 k

D. 10 k

Answer: Option A

.

13. If the primary power of an ideal transformer having a 2:1 voltage ratio is 100 W, the secondary power is

A. 100 W

B. 50 W

C. 75 W

D. 200 W

Answer: Option A

.

14. A transformer has

A.

primary and secondary windings, both of which are considered inputs

B.

primary and secondary windings, both of which are considered outputs

C.

a primary winding used as an output and a secondary winding used as an input

D.

a primary winding used as an input and a

secondary winding used as an output

Answer: Option D

XVII - Time Response of Reactive Circuits

1.

What voltage will the capacitor charge up to in the given circuit for the single input pulse shown?

A. 3.15 V

B. 4.3 V

C. 4.75 V

D. 4.9 V

Answer: Option B

.

2. If a periodic pulse waveform is applied to an RC differentiating circuit, which two conditions are possible?

A. tw 5 or tw > 5

B. tw = 5 or tw > 5

C. tw 5 or tw < 5

D. tw 5 or tw < 5

Answer: Option D

.

3. An RL integrator and an RC differentiator can act as what types of filters, respectively?

A. low-pass, low-pass

B. low-pass, high-pass

C. high-pass, high-pass

D. high-pass, low-pass

Answer: Option B

.

4. In a repetitive-pulse RC integrator circuit, what would the steady-state voltage equal at the end of the fifth pulse? Assume a Vin of 20 V.

A. 1.46 V

B. 14.62 V

C. 20 V

D. 0 V

Answer: Option B

.

5.

What is a circuit that produces short-duration spikes?

A. A trigger pulse generator

B. An RL integrator

C. A timing circuit

D. A pulse waveform-to-dc converter

Answer: Option A 6.

In the given circuit, what must the pulse width and time between pulses be to allow the capacitor to

completely charge by the end of each pulse and to completely discharge between each pulse?

A. 940 s

B. 2.82 ms

C. 3.76 ms

D. 4.7 ms

Answer: Option D

.

7.

The given circuit is an

A. RL integrator

B. RC differentiator

C. RL differentiator

D. RC integrator

Answer: Option D

.

8. Which of the following is true for a capacitor?

A.

A capacitor acts like a short to instantaneous changes in current.

B.

A capacitor's voltage cannot change instantaneously.

C. A capacitor acts like an open to dc.

D. All of the above

Answer: Option D

.

9. If the capacitor in an RC integrator shorts, the output

A. is at ground

B. would measure the same as the input

C. would measure zero volts


Answer: Option A

.

10

.

What has the voltage across the resistor decayed to by the end of the pulse in the given circuit?

A. 0 V

B. 0.75 V

C. 5.55 V

D. 14.25 V

Answer: Option B 11

.

How long will it take the capacitor in the given circuit to discharge?

A. 16.4 s

B. 32.8 s

C. 65.6 s

D. 82 s

Answer: Option D

.

12

.

What is the voltage across the inductor in the given circuit on the falling edge of the first input pulse?

A. –0.2 V

B. 0.2 V

C. –9.8 V

D. 9.8 V

Answer: Option A

XVIII - TRANSISTORS AND APPLICATIONS

1. The primary function of the bias circuit is to

A. hold the circuit stable at VCC

B. hold the circuit stable at vin

C. ensure proper gain is achieved

D. hold the circuit stable at the designed Q-point

Answer: Option D

.

2. A JFET

A. is a current-controlled device

B. has a low input resistance

C. is a voltage-controlled device

D. is always forward-biased

Answer: Option C

.

3. A source follower has a voltage gain (Av) of

A. AV = gmRd

B. AV = gmRS

C.

D.

Answer: Option C

.

4. The capacitor that produces an ac ground is called a(n)

A. coupling capacitor

B. dc open

C. bypass capacitor

D. ac open

Answer: Option C

.

5. The formula used to calculate the approximate ac resistance of the base-emitter diode (re) is

A.

B. re 25 mV × IC

C.

D.

Answer: Option A 6. The signal voltage gain of an amplifier, Av, is defined

as:

A.

B. Av = IC × RC

C.

D.

Answer: Option C

.

7. In a class B push-pull amplifier, the transistors are biased slightly above cutoff to avoid

A. crossover distortion

B. unusually high efficiency

C. negative feedback

D. a low input impedance

Answer: Option A

.

8. The depletion-mode MOSFET

A. can operate with only positive gate voltages

B. can operate with only negative gate voltages

C. cannot operate in the ohmic region

D.

can operate with positive as well as negative

gate voltages

Answer: Option D

.

9. Three different points are shown on a dc load line. The

upper point represents the

A. minimum current gain

B. quiescent point

C. saturation point

D. cutoff point

Answer: Option C

.

10. Which of the following conditions are needed to properly bias an npn transistor amplifier?

A.

Forward bias the base/emitter junction and

reverse bias the base/collector junction.

B.

Forward bias the collector/base junction and

reverse bias the emitter/base junction.

C.

Apply a positive voltage on the n-type

material and a negative voltage on thep-type material.

D. Apply a large voltage on the base.

Answer: Option A 11. Often a common-collector will be the last stage

before the load; the main function of this stage is to

A. provide voltage gain

B.

buffer the voltage amplifiers from the low-resistance load

C. provide phase inversion

D.

provide a high-frequency path to improve the

frequency response

Answer: Option B

.

12. In order for feedback oscillators to have any practical value, the gain has to be

A. < 1

B. self-adjusting

C. stabilized

D. nonlinear

Answer: Option B

.

13. To get a negative gate-source voltage in a self-biased JFET circuit, you must use a

A. voltage divider

B. source resistor

C. ground

D. negative gate supply voltage

Answer: Option B

XIX - Basic Op-Amp Circuits

1. The center frequency of a band-pass filter is always equal to the

A. bandwidth

B. –3 dB frequency

C. bandwidth divided by Q

D. geometric average of the critical frequencies

Answer: Option D

.

2.

The formula shows that for a given

capacitor, if the voltage changes at a constant rate with respect to time, the current will

A. increase

B. decrease

C. be constant

D. decrease logarithmically

Answer: Option C

.

3. A zero-level detector is a

A. comparator with a sine-wave output

B. comparator with a trip point referenced to zero

C. peak detector

D. limiter

Answer: Option B

.

4. A digital-to-analog converter is an application of the

A. scaling adder

B. voltage-to-current converter

C. noninverting amplifier

D. adjustable bandwidth circuit

Answer: Option A

.

5. If the value of resistor Rf in an averaging amplifier circuit is equal to the value of one input resistor divided by the number of inputs, the output will be equal to

A. the average of the individual inputs

B.

the inverted sum of the individual inputs

C. the sum of the individual inputs

D.

the inverted average of the individual inputs

Answer: Option D 6. If the input to a comparator is a sine

wave, the output is a

A. ramp voltage

B. sine wave

C. rectangular wave

D. sawtooth wave

Answer: Option C

.

7. A basic series regulator has

A. an error detector

B. a load

C. a reference voltage

D.

both an error detector and a reference voltage

Answer: Option D

.

8. A comparator is an example of a(n)

A. active filter

B. current source

C. linear circuit

D. nonlinear circuit

Answer: Option D

.

9. Initially, the closed-loop gain (Acl) of a Wien-bridge oscillator should be

A. Acl < 3

B. Acl > 3

C. 0

D. Acl 1

Answer: Option B

.

10. In an averaging amplifier, the input resistances are

A.

equal to the feedback resistance

B.

less than the feedback resistance

C.

greater than the feedback

resistance

D. unequal

Answer: Option C

11. A triangular-wave oscillator can consist of an op-amp comparator, followed by a(n)

A. differentiator B. amplifier

C. integrator D. multivibrator

Answer: Option C

.

12. The ramp voltage at the output of an op-amp integrator

A. increases or decreases at a linear rate

B. increases or decreases exponentially

C. is always increasing and never decreasing

D. is constant

Answer: Option A

.

13. A two-pole high-pass active filter would have a roll-off rate of

A. 40 dB/decade

B. –40 dB/decade

C. 20 dB/decade

D. –20 dB/decade

Answer: Option B

XX - SPECIAL-PURPOSE OP-AMP CIRCUITS

1

.

Which circuit is known as a current-to-voltage converter?

A. a B. b

C. c D. d

Answer: Option A

.

2. When using an OTA in a Schmitt-trigger configuration, the trigger points are controlled by

A. the Iout

B. the IBIAS

C. the Vout

D. both Iout and IBIAS

Answer: Option D

.

3

.

Refer the given circuits. Which circuit is known as an OTA?

A. a B. b

C. c D. d

Answer: Option D

.

4.

This circuit is a setup for

A. an antilog amplifier

B. a constant-current source

C. an instrumentation amplifier

D. an isolation amplifier

Answer: Option C

.

5.

Which circuit is known as a voltage-to-current converter?

A. a B. b

C. c D. d

Answer: Option B

6. The primary function of the oscillator in an isolation amplifier is to

A.

convert dc to high-

frequency ac

B.

convert dc to low-

frequency ac

C.

rectify high-frequency ac to dc

D.

produce dual-polarity dc voltages for the input to the demodulator

Answer: Option A

.

7.

Refer to Figure 20-2. This circuit is a setup for


B.

a constant-current source

C.

an instrumentation amplifier


Answer: Option B

.

8. An instrumentation amplifier has a high

A. output impedance

B. power gain

C. CMRR

D. supply voltage

Answer: Option C

.

9

.

This circuit is a setup for


B.

a constant-current source

C.

an instrumentation amplifier


Answer: Option D

.

10. Circuits that shift the dc level of a signal are called

A. limiters

B. clampers

C. peak detectors

D. dc converters

Answer: Option B

1

1

.

The voltage gain of an OTA can be calculated using the formula

A.

B.

C.

D.

Answer: Option B

.

12. In the classic three-op-amp instrumentation amplifier, the differential voltage gain is usually produced by the

A. first stage

B. second stage

C. mismatched resistors

D. output op-amp

Answer: Option A

XXI - Measurement, Conversion and Control

1. What device is similar to an RTD but has a negative temperature coefficient?

A. Strain gauge

B. Thermistor

C. Negative-type RTD

D. Thermocouple

Answer: Option B

.

2. The resistive change of a strain gauge

A. is based on the weight placed upon it, but can be many thousands of ohms

B. is usually no more than 100

C. is based on the gauge factor, but is typically less than an ohm

D. has a positive temperature coefficient

Answer: Option C

.

3. The silicon-controlled rectifier can be turned off

A. by a negative gate pulse

B. by forced commutation

C. with the off switch

D. when the breakover voltage is exceeded

Answer: Option B

.

4. The output voltage of a typical thermocouple is

A. less than 100 mV

B. greater than 1 V

C. Thermocouples vary resistance, not voltage.


Answer: Option A

.

5. The connections to a thermocouple

A. can produce an unwanted thermocouple effect, which must be compensated for

B. produce an extra desirable thermocouple effect

C. must be protected, since high voltages are present

D.

produce an extra desirable thermocouple effect and must be protected, since high voltages

are present

Answer: Option A

6. What is the zero-voltage switch used for?

A.

To reduce

radiation of high frequencies during turn-on of a high current to a load

B.

To control

low-voltage circuits

C.

To provide power to a

circuit when power is lost

D.

For extremely low-voltage applications

Answer: Option A

.

7. Temperature sensing can be achieved by the use of

A. thermocouples

B. RTDs

C. thermistors

D. All of the above

Answer: Option D

.

8. The purpose of compensation for a thermocouple is

A. to decrease temperature sensitivity

B. to increase voltage output

C.

to cancel unwanted voltage output of a

thermocouple

D. used for high-temperature circuits

Answer: Option C

.

9. The change in value of an analog signal during the conversion process produces what is called the

A. quantization error

B. resolution error

C. Nyquist error

D. sampling error

Answer: Option A

.

10. Which of the following performance specifications applies to a sample-and-hold circuit?

A. Aperture time

B. Aperture droop

C. Feedback

D. Acquisition jitter

Answer: Option A 11. RTDs are typically connected with other fixed resistors

A. in a pi configuration

B. in a bridge configuration

C. and variable resistors

D. and capacitors in a filter-type circuit

Answer: Option B

.

12. Holding current for an SCR is best described as

A. the minimum current required for turn-off

B. the current required before an SCR will turn on

C.

the amount of current required to maintain conduction

D.

the gate current required to maintain conduction

Answer: Option C

.

13. What is the moving part of a linear variable differential transformer?

A. Primary B. Secondary

C. Diaphragm D. Core

Answer: Option D

XXII - Resistance and Power

1. The resistivity of copper is:

A. 9.9

B. 10.7

C. 16.7

D. 17.0

Answer: Option B

.

2. How do fixed resistors usually fail?

A. slowly over time

B. by increasing their value

C. by becoming an open circuit

D.

by increasing their value and becoming an open

circuit

Answer: Option C

.

3. With Ohm's law, if voltage increases and resistance stays the same:

A. current remains the same

B. power decreases

C. current increases

D. resistance decreases

Answer: Option C

.

4. Which formula shows a direct proportionality between power and voltage?

A. V = IR

B. P = VI

C. P = IR

D. I = V/R

Answer: Option B

.

5. With 1 mA of current, what wattage rating should a 470 ohm resistor have?

A. 1/4 watt

B. 1/2 watt

C. 1 watt

D. 2 watts

Answer: Option A

6. How is a 3.9 k resistor color-coded?

A. red, white, red, gold

B. red, green, orange, silver

C. orange, white, red, gold

D. orange, green, orange, silver

Answer: Option C

.

7. What resistor type is found in SIPs and DIPs?

A. metal film

B. wirewound

C. metal oxide

D. thick film

Answer: Option D

.

8. Ohm's law is not:

A. V = IR

B. I = V/R

C. R = IV

D. R = V/I

Answer: Option C

.

9. What are the two major categories for resistors?

A. low and high ohmic value

B. commercial and industrial

C. low and high power value

D. fixed and variable

Answer: Option D

.

10.

How many connections does a potentiometer have?

A. 1 B. 2

C. 3 D. 4

Answer: Option C

A potentiometer uses three connections, as opposed to a rheostat, which only employs two. Having three connections allows the potentiometer to vary voltage. Both the potentiometer and the rheostat are classified as variable resistors.

11.

What current is flowing in the circuit?

A. 288 kA

B. 2 kA

C. 50 mA

D. 500 A

Answer: Option D

.

12. The six basic forms of energy are:

A.

light, sun, magnetic, chemical, electrical, and mechanical

B.

electrical, mechanical, light, heat, magnetic,

and chemical

C.

electrical, mechanical, sun, heat, chemical, and

light

D.

potential, sun, light, chemical, electrical, and

mechanical

Answer: Option B

.

13. How much energy is stored if 6.24 x 1018 electrons are stored in 4 volts?

A. 4 joules

B. 1.56 x 1018 electrons

C. 1.56 coulombs

D. 2.496 x 1019 electrons

Answer: Option A

.

14. With Ohm's law:

A. current is inversely proportional to resistance

B. resistance is directly proportional to voltage

C. voltage is indirectly proportional to power

D. current is directly proportional to resistance

Answer: Option A

.

15. Power is defined as:

A. the rate at which energy is used

B. watts

C. energy

D. the rate at which energy is generated

Answer: Option A 16. What is the most commonly used conductor in

electronics?

A. aluminum B. copper

C. gold D. silver

Answer: Option B

.

17. With Ohm's law, no change in resistance means that current and voltage will be:

A. directly proportional

B. unable to produce energy

C. the same

D. inversely proportional

Answer: Option A

.

18. A potentiometer has how many leads?

A. 1 B. 2

C. 3 D. 4

Answer: Option C

.

19. What is the ratio of 13 to 47 expressed in percent?

A. 2.76% B. 27.7%

C. 3.60% D. 36.1%

Answer: Option B

.

20. What happens to current and resistance if the voltage doubles?

A. Current doubles and resistance doubles.

B. Current doubles and resistance is halved.

C.

Current remains the same and resistance

doubles.

D.

Current doubles and resistance remains the

same.

Answer: Option D 21. One problem with mechanically variable resistors is

noticeable in audio circuits as:

A. scratchy noise

B. lack of bass response

C. variable volume

D. too much treble response

Answer: Option A

.

22. A color code of orange, orange, orange is for what ohmic value?

A. 22 kilohms

B. 3300 ohms

C. 44000 ohms

D. 33 kilohms

Answer: Option D

.

23. A conductor's cross-sectional area in circular mils

for inch is:

A. 500 cmils

B. 100,000 cmils

C. 1,000,000 cmils

D. 500,000,000 cmils

Answer: Option C

.

24. If a variable resistor's resistance varies in a nonuniform manner as the shaft is moved, it is considered to be:

A. linear

B. defective

C. not wirewound

D. tapered

Answer: Option D

.

25. Power is measured in units of:

A. joules x charge

B. joules/work

C. joules x voltage

D. joules/time

Answer: Option D 26. How many basic types of resistors exist?

A. 1 B. 2

C. 3 D. 4

Answer: Option B

.

27. With a complex circuit, a supply source senses:

A. open circuit components

B. when voltages need to be increased

C. only a single resistive connection

D. when complex currents are needed

Answer: Option C

.

28. How many ohms of resistance allows a current of

720 A to flow when 3.6 kV is applied?

A. 200 n

B. 5 k

C. 200 k

D. 5 M

Answer: Option D

.

29. Which is the most important step utilized when measuring resistors?

A. use the highest possible scale

B. keep test leads short

C. zero the meter before using

D. remove power from the circuit

Answer: Option D

.

30. Components designed to oppose the flow of current are called:

A. insulators

B. conductors

C. resistors

D. heat exchangers

Answer: Option C 31. How many amps are used by a 100 watt, 120 volt light

bulb?

A. 1.2 amps

B. 12000 amps

C. 830 mA

D. 12 amps

Answer: Option C

.

32. The source is 24 volts and the load resistance is

100 . What is the load current?

A. 2.4 A

B. 240 mA

C. 24 mA

D. 2.4 mA

Answer: Option B

.

33. Resistors are identified as to wattage by:

A. size

B. color code

C. types of materials

D. internal construction

Answer: Option A

.

34. What type of resistors have a tolerance rating of 5% or greater?

A. precision B. SIP

C. general-purpose D. wirewound

Answer: Option C

.

35. Resistor tolerance is either printed on the component, or is provided by:

A. keyed containers

B. size

C. color code

D. ohmmeter reading

Answer: Option C 36. How many connections does a rheostat have?

A. 1 B. 2

C. 3 D. 4

Answer: Option B

.

37. What are the parts of a rheostat?

A. wiper and resistor track

B. solenoid and armature

C. contact and wire wound

D. center tape and wiper

Answer: Option A

.

38. The load resistance increases. How will the load current change?

A. vary

B. remain constant

C. increase

D. decrease

Answer: Option D

.

39. What is the power dissipated by a 1.2 k resistor with

12 volts across it?

A. 12 A

B. 1.2 A

C. .12 A

D. 12 mA

Answer: Option C

.

40. How many joules of energy will a 10 W lamp dissipate in one minute?

A. 10 joules

B. 60 joules

C. 600 joules

D. 3600 joules

Answer: Option C

41. Which type of test equipment is used to measure resistors?

A. ohmmeter

B. ammeter

C. voltmeter

D. watt meter

Answer: Option A

.

42. Resistance is:

A.

the opposition to current flow accompanied by the dissipation of heat

B.

symbolized by R, measured in ohms, and

directly proportional to conductance

C. directly proportional to current and voltage

D.

represented by the flow of fluid in the fluid circuit

Answer: Option A

.

43. Electrical equipment is protected against excessive current by a(n):

A. fusible wire link

B. insulated glass container

C. metal ended coil

D. circuit opener

Answer: Option A

.

44. If resistance decreases, then current will:

A. decrease

B. increase

C. remain the same

D. double

Answer: Option B

.

45. A wire with a smaller cross-sectional area will produce:

A. less heat

B. more conductance

C. less resistance

D. more heat

Answer: Option D

46. A 22-gauge wire will have a diameter in mils of:

A. 10.03 B. 22.35

C. 45.26 D. 71.96

Answer: Option B

.

47. The word work means that:

A. energy has been transferred

B. it is inversely related to energy

C. no energy has been transferred

D. work and energy are not related

Answer: Option A

.

48. A good fuse will have:

A. zero ohms resistance

B. a medium resistance

C. a high resistance

D. an infinite resistance

Answer: Option A

.

49. What property does an incandescent lamp possess?

A. cold resistance

B. hot resistance

C. ballast resistance

D. both cold and hot resistance

Answer: Option D

.

50. One advantage of a carbon film resistor over a carbon composition resistor is:

A. less circuit noise

B. smaller size

C. higher wattage

D. poor tolerance

Answer: Option A 51. If a metallic conductor has a positive temperature

coefficient of resistance, then:

A. as temperature increases, resistance decreases

B. as current increases, resistance decreases

C. as voltage increases, current increases

D. as temperature increases, resistance increases

Answer: Option D

.

52. What value of a 1.3 k resistor as measured by a digital voltmeter would be considered within tolerance?

A. 1234

B. 1235

C. 1366

D. 1367

Answer: Option B

.

53. If a calculator display was "0.00263," what would this answer be in percent?

A. 0.026% B. 0.26%

C. 2.63% D. 26.3%

Answer: Option B

.

54. A 33 k resistor with a 20% tolerance checks out as

ok with which of the following ohmmeter readings?

A. 26400 ohms

B. 24183 ohms

C. 6600 ohms

D. 39970 ohms

Answer: Option A

.

55. For P = V2/R, a decrease in resistance should produce:

A. a decrease in power

B. an increase in ohms

C. an increase in power

D. a decrease in current

Answer: Option C 56. After a lamp is turned on, its filament resistance will

change to become:

A. less resistive

B. cooler

C. brighter

D. more resistive

Answer: Option D

.

57. Wirewound resistors are usually used in circuits that have:

A. high current

B. negative temperature coefficients

C. low power

D. high voltage

Answer: Option A

.

58. How is power dissipated in a resistor?

A. by resistance

B. by voltage

C. by current

D. by heat

Answer: Option D

.

59. Resistance in a circuit is:

A. opposition to current

B. opposition to voltage

C. the same as current

D. the same as voltage

Answer: Option A

.

60. The unit designator for resistance value is the:

A. ampere B. ohm

C. volt D. watt

Answer: Option B

61. One ampere of current flowing through one ohm of resistance is equal to:

A. 1 horsepower

B. 1 Btu

C. 1 watt

D. 1 joule

Answer: Option C

.

62. Good insulators:

A. have few electrons in their outer shells

B. have a large dielectric strength

C. have a small breakdown voltage

D. have many electrons in the nucleus

Answer: Option B

XXIII - ALTERNATING CURRENT VS DIRECT CURRENT

1. What are the two main applications for ac?

A. direct, pulsating

B. electric, magnetic

C. power, information

D. static, dynamic

Answer: Option C

.

2. The distance that a signal's energy can travel in the time it takes for one cycle to occur is called the signal's:

A. amplitude B. frequency

C. wavelength D. period

Answer: Option C

.

3. One oscilloscope selector knob that allows the major and minor divisions of the graticule to be used to determine a signal amplitude value is called the:

A. time/cm control

B. position control

C. intensity control

D. volts/cm control

Answer: Option D

.

4. If current varies periodically from zero to a maximum, back to zero, and then repeats, the signal is:

A. direct B. alternating

C. pulsating D. repetitive

Answer: Option C

.

5. What voltage will an ac voltmeter display?

A. rms B. average

C. peak D. peak-to-peak

Answer: Option A 6. What is the peak value of a household appliance that

uses a 230 V ac source?

A. 163 V

B. 230 V

C. 325 V

D. 480 V

Answer: Option C

.

7. What is the waveform period difference between the 60 Hz electricity used in this country and the 50 Hz used in Europe?

A. 3 ms

B. 16 ms

C. 4 ms

D. 20 ms

Answer: Option A

.

8. Test equipment selection enables the technician to both generate signals and:

A. change circuit conditions

B. inject signals

C. sense circuit conditions

D. change signal frequencies

Answer: Option C

.

9. Why is ac current transfer more effective than dc current transfer over long distances?

A. due to the height of power lines

B. due to the use of ac generators

C.

due to step-up and step-down transformers

reducing I2R losses

D. due to very high voltages

Answer: Option C

.

10. A sine wave reaches maximum positive voltage at:

A. 90° B. 0°

C. –90° D. 360°

Answer: Option A 11. Which percentages of full-amplitude rise time are used

for a pulse wave?

A. 0 to 50 percent

B. 0 to 100 percent

C. 5 to 95 percent

D. 10 to 90 percent

Answer: Option D

.

12. What is the average value of a 12 V peak wave?

A. 3.82 V

B. 4.24 V

C. 7.64 V

D. 9.42 V

Answer: Option C

.

13. A test equipment item that has the ability to produce either square, triangular, or sawtooth waveforms is called:

A. a function generator

B. a radio frequency generator

C. an audio frequency generator

D. a frequency meter or counter

Answer: Option A

.

14. The current is flowing in what direction?

A. clockwise

B. counterclockwise

C. in both directions at the same time

D.

50% of the time clockwise and 50% of the time

counterclockwise

Answer: Option D

.

15. What does the CRT oscilloscope display?

A. voltage and period

B. current and frequency

C. rms voltage and current

D. frequency and voltage

Answer: Option A 16. Power companies supply ac, not dc, because:

A. it is easier to transmit ac

B. there is no longer a need for dc

C. dc is more dangerous

D. there are not enough batteries

Answer: Option A

.

17. If a waveform period is determined to be 10 microseconds in duration, what is the frequency of the signal?

A. 100 Hz

B. 1000 Hz

C. 10 kHz

D. 100 kHz

Answer: Option D

.

18. The phase difference between sine waves of different frequencies is:

A. equal to their frequency differences

B. the difference in their fixed time displacement

C. the same throughout time

D. constantly changing

Answer: Option B

.

19. If a sine wave signal is 100 mV peak-to-peak, how many volts would be measured by a voltmeter?

A. 14.14 mV

B. 35.4 mV

C. 63.7 mV

D. 70.7 mV

Answer: Option B

.

20. What term expresses the frequency of a rectangular wave?

A. Hz B. period

C. PRF D. PRT

Answer: Option C

21. AC effective voltage is named:

A. average

B. peak

C. peak-to-peak

D. root mean square

Answer: Option D

.

22. If a voltmeter measures a sine wave as 500 mV, what would be its average value?

A. 159.0 mV

B. 318.5 mV

C. 353.5 mV

D. 451.0 mV

Answer: Option B

.

23. One adjustable knob on the oscilloscope that allows the trace to be aligned with a reference graticule is called the:

A. position control

B. focus control


D. volts/cm control

Answer: Option A

.

24. Signal comparisons may be most easily seen when using which item of test equipment?

A. spectrum analyzer

B. multimeter

C. function generator

D. dual trace oscilloscope

Answer: Option D

.

25. The magnitude that an alternation varies from zero is called its:

A. altitude B. amplitude

C. attitude D. polarity

Answer: Option B

26. The power that is distributed from a power plant to your home is:

A. high voltage to high voltage

B. low voltage to high voltage

C. high voltage to low voltage

D. low voltage to low voltage

Answer: Option C

.

27. A rectangular wave that has a duty cycle of 50 percent could be called a:

A. c wave

B. sawtooth wave

C. square wave

D. triangle wave

Answer: Option C

.

28. A triangle wave consists of repeating:

A. positive ramps only

B. negative ramps only

C. positive and negative ramps of equal value

D. positive and negative ramps of unequal value

Answer: Option C

.

29. What is the name of a device used to directly measure the frequency of a periodic wave?

A. oscilloscope

B. frequency meter or counter

C. audio frequency generator

D. radio frequency generator

Answer: Option B

.

30. Which control should be moved to display more cycles of a signal on an oscilloscope?

A. horizontal position to left or right

B. volts/cm to a smaller number

C. vertical position to top or bottom

D. time/cm to a higher setting

Answer: Option D 31. What is the name of a device that converts

sound waves to electrical waves?

A. an amplifier

B. an antenna

C. a filter

D. a microphone

Answer: Option D

.

32. If the frequency of a radio wave is increased, then its wavelength will:

A. increase

B. decrease

C. remain the same

D. cannot tell

Answer: Option B

.

33. What is the rms voltage value of an ac signal whose peak oscilloscope display uses 3 major divisions above the zero setting? (V/cm = 5)

A. 5.3 V

B. 10.6 V

C. 15.0 V

D. 21.2 V

Answer: Option B

.

34. What is the peak-to-peak current value when an ammeter measures a 20 mA value?

A. 14 mA

B. 28 mA

C. 40 mA

D. 57 mA

Answer: Option D

.

35. How long would it take to transmit an electromagnetic wave to a receiving antenna 1,000 miles away?

A. 5.38 ms

B. 10.8 ms

C. 53.8 ms

D. 108 ms

Answer: Option A

36. What is the waveform period of a square wave signal that horizontally covers 3 major divisions per cycle? (time/cm = 50 ms)

A. 50 ms

B. 100 ms

C. 150 ms

D. 200 ms

Answer: Option C

.

37. A sine wave has:

A. four quadrants

B. two alternations

C. one period

D. all of the above

Answer: Option D

.

38. What is the peak-to peak voltage of a 56 Vrms ac voltage?

A. 158 V

B. 164 V

C. 82 V

D. 79 V

Answer: Option A

.

39. One oscilloscope selector knob that allows the major and minor divisions of the graticule to be used to determine a waveform period is called a:

A. focus control

B. time/cm control


D. volts/cm control

Answer: Option B

.

40. What is the period of a 16 MHz sine wave?

A. 196 ns

B. 62.5 ns

C. 31.25 ns

D. 19.9 ns

Answer: Option B

XXIV - Semiconductor Principles

1. Intrinsic semiconductor material is characterized by a valence shell of how many electrons?

A. 1 B. 2

C. 4 D. 6

Answer: Option C

.

2. Ionization within a P-N junction causes a layer on each side of the barrier called the:

A. junction

B. depletion region

C. barrier voltage

D. forward voltage

Answer: Option B

.

3. What is the most significant development in electronics since World War II?

A. the development of color TV

B. the development of the diode

C. the development of the transistor

D. the development of the TRIAC

Answer: Option C

.

4. What causes the depletion region?

A. doping

B. diffusion

C. barrier potential

D. ions

Answer: Option B

.

5. What is an energy gap?

A. the space between two orbital shells

B.

the energy equal to the energy acquired

by an electron passing a 1 V electric field

C.

the energy band in which electrons can

move freely

D.

an energy level at which an electron can exist

Answer: Option A 6. Silicon atoms combine into an orderly

pattern called a:

A. covalent bond

B. crystal

C. semiconductor

D. valence orbit

Answer: Option B

.

7. In "n" type material, majority carriers would

be:

A. holes B. dopants

C. slower D. electrons

Answer: Option D

.

8. Elements with 1, 2, or 3 valence electrons usually make excellent:

A. conductors B. semiconductors

C. insulators D. neutral

Answer: Option A

.

9. A commonly used pentavalent material is:

A. arsenic B. boron

C. gallium D. neon

Answer: Option A

.

10. Which material may also be considered a semiconductor element?

A. carbon B. ceramic

C. mica D. argon

Answer: Option A

11. In "p" type material, minority carriers would be:

A. holes B. dopants

C. slower D. electrons

Answer: Option D

The purpose of p-type doping is to create an abundance of holes. In the case of silicon, a trivalent atom (typically from Group 13 of the periodic table, such as boron or aluminium) is substituted into the crystal lattice. The result is that one electron is missing from one of the four covalent bonds normal for the silicon lattice. Thus the dopant atom can accept an electron from a neighboring atom's covalent bond to complete the fourth bond. This is why such dopants are called acceptors. The dopant

atom accepts an electron, causing the loss of half of one bond from the neighboring atom and resulting in the formation of a "hole". Each hole is associated with a nearby negatively charged dopant ion, and the semiconductor remains electrically neutral as a whole. However, once each hole has wandered away into the lattice, one proton in the atom at the hole's location will be "exposed" and no longer cancelled by an electron. This atom will have 3 electrons and 1 hole surrounding a particular nucleus with 4 protons. For this reason a hole behaves as a positive charge. When a sufficiently large number of acceptor atoms are added, the holes greatly outnumber thermal excited electrons. Thus, holes are the majority carriers, while electrons become minority carriers in p-type materials.

12. What can a semiconductor sense?

A. magnetism

B. temperature

C. pressure

D. all of the above

Answer: Option D

.

13. When an electron jumps from the valence shell to the conduction band, it leaves a gap. What is this gap called?

A. energy gap

B. hole

C. electron-hole pair

D. recombination

Answer: Option B

.

14. Forward bias of a silicon P-N junction will produce a barrier voltage of approximately how many volts?

A. 0.2 B. 0.3

C. 0.7 D. 0.8

Answer: Option C

.

15. Which semiconductor material is made from coal ash?

A. germanium B. silicon

C. tin D. carbon

Answer: Option A

16. When and who discovered that more than one transistor could be constructed on a single piece of semiconductor material:

A. 1949, William Schockley

B. 1955, Walter Bratten

C. 1959, Robert Noyce

D. 1960, John Bardeen

Answer: Option C

.

17. When is a P-N junction formed?

A. in a depletion region

B.

in a large reverse biased

region

C.

the point at which two

opposite doped materials come together

D.

whenever there is a

forward voltage drop

Answer: Option C

.

18. A P-N junction mimics a closed switch when it:

A.

has a low junction resistance

B. is reverse biased

C.

cannot overcome its

barrier voltage

D.

has a wide depletion

region

Answer: Option A

.

19. Solid state devices were first manufactured during:

A. World War 2

B. 1904

C. 1907

D. 1960

Answer: Option D

.

20. Electron pair bonding occurs when atoms:

A. lack electrons

B. share holes

C. lack holes

D. share electrons

Answer: Option D

21. How many valence electrons are in every semiconductor material?

A. 1 B. 2

C. 3 D. 4

Answer: Option D

.

22. What is a type of doping material?

A. extrinsic semiconductor material

B. pentavalent material

C. n-type semiconductor

D. majority carriers

Answer: Option B

.

23. Minority carriers are many times activated by:

A. heat

B. pressure

C. dopants

D. forward bias

Answer: Option A

.

24. What is the voltage across R1 if the P-N junction is made of silicon?

A. 12 V

B. 11.7 V

C. 11.3 V

D. 0 V

Answer: Option C

.

25. If conductance increases as temperature increases, this is known as a:

A. positive coefficient

B. negative current flow

C. negative coefficient

D. positive resistance

Answer: Option C

A negative temperature coefficient (NTC) occurs when the thermal conductivity of a material rises with increasing temperature, typically in a defined temperature range.

26. Which of the following cannot actually move?

A. majority carriers

B. ions

C. holes

D. free electrons

Answer: Option B

.

27. What electrical characteristic of intrinsic semiconductor material is controlled by the addition of impurities?

A. conductivity

B. resistance

C. power

D. all of the above

Answer: Option A

XXV- BIPOLAR JUNCTION TRANSISTORS (BJT)

1. When transistors are used in digital circuits they usually operate in the:

A. active region

B. breakdown region

C. saturation and cutoff regions

D. linear region

Answer: Option C

.

2. Three different Q points are shown on a dc load line. The upper Q point represents the:

A. minimum current gain

B. intermediate current gain

C. maximum current gain

D. cutoff point

Answer: Option C

.

3.

A transistor has a of 250 and a base current, IB, of

20 A. The collector current, IC, equals:

A. 500 A

B. 5 mA

C. 50 mA

D. 5 A

Answer: Option B

.

4. A current ratio of IC/IE is usually less than one and is called:

A. beta B. theta

C. alpha D. omega

Answer: Option C

.

5. With the positive probe on an NPN base, an ohmmeter reading between the other transistor terminals should be:

A. open

B. infinite

C. low resistance

D. high resistance

Answer: Option C

6. In a C-E configuration, an emitter resistor is used for:

A. stabilization

B. ac signal bypass

C. collector bias

D. higher gain

Answer: Option A

.

7. Voltage-divider bias provides:

A. an unstable Q point

B. a stable Q point

C.

a Q point that easily varies with changes in the

transistor's current gain

D.

a Q point that is stable and easily varies with

changes in the transistor’s current gain

Answer: Option B

.

8. To operate properly, a transistor's base-emitter junction must be forward biased with reverse bias applied to which junction?

A. collector-emitter B. base-collector

C. base-emitter D. collector-base

Answer: Option D

.

9. The ends of a load line drawn on a family of curves determine:

A. saturation and cutoff

B. the operating point

C. the power curve

D. the amplification factor

Answer: Option A

.

10. If VCC = +18 V, voltage-divider resistor

R1 is 4.7 k , and R2 is 1500 , what is

the base bias voltage?

A. 8.70 V

B. 4.35 V

C. 2.90 V

D. 0.7 V

Answer: Option B 11. The C-B configuration is used to provide

which type of gain?


C. resistance D. power

Answer: Option A

.

12. The Q point on a load line may be used to determine:

A. VC B. VCC

C. VB D. IC

Answer: Option C

.

13. A transistor may be used as a switching device or as a:

A. fixed resistor

B. tuning device

C. rectifier

D. variable resistor

Answer: Option D

.

14. If an input signal ranges from 20–40 A

(microamps), with an output signal ranging from .5–1.5 mA (milliamps), what is the ac beta?

A. 0.05 B. 20

C. 50 D. 500

Answer: Option C

.

15. Which is beta's current ratio?

A. IC/IB B. IC/IE

C. IB/IE D. IE/IB

Answer: Option A

16. A collector characteristic curve is a graph showing:

A.

emitter current (IE) versus collector-emitter voltage (VCE) with (VBB) base bias voltage held constant

B.

collector current (IC) versus collector-emitter voltage (VCE) with (VBB) base bias voltage held constant

C.

collector current (IC) versus collector-emitter voltage (VC) with (VBB) base bias voltage held constant

D.

collector current (IC) versus collector-emitter voltage (VCC) with (VBB) base bias voltage held constant

Answer: Option B

.

17. With low-power transistor packages, the base terminal is usually the:

A. tab end

B. middle

C. right end

D. stud mount

Answer: Option B

.

18. When a silicon diode is forward biased, what is VBE for

a C-E configuration?

A. voltage-divider bias

B. 0.4 V

C. 0.7 V

D. emitter voltage

Answer: Option C

.

19. What is the current gain for a common-base configuration where IE = 4.2 mA and IC= 4.0 mA?

A. 16.80 B. 1.05

C. 0.20 D. 0.95

Answer: Option D

.

20. With a PNP circuit, the most positive voltage is probably:

A. ground B. VC

C. VBE D. VCC

Answer: Option A 21. If a 2 mV signal produces a 2 V output,

what is the voltage gain?

A. 0.001 B. 0.004

C. 100 D. 1000

Answer: Option D

.

22. The symbol hfe is the same as:

A.

B.

C. hi-fi

D.

Answer: Option A

.

23. Most of the electrons in the base of an NPN transistor flow:

A. out of the base lead

B. into the collector

C. into the emitter

D. into the base supply

Answer: Option B

.

24. In a transistor, collector current is controlled by:

A. collector voltage

B. base current

C. collector resistance

D. all of the above

Answer: Option B

.

25. Total emitter current is:

A. IE – IC

B. IC + IE

C. IB + IC

D. IB – IC

Answer: Option C

26. Often a common-collector will be the last stage before the load; the main function(s) of this stage is to:

A. provide voltage gain

B. provide phase inversion

C.

provide a high-frequency path to improve the frequency response

D.

buffer the voltage amplifiers

from the low-resistance load and provide impedance matching for maximum power transfer

Answer: Option D

.

27. For a C-C configuration to operate properly, the collector-base junction should be reverse biased, while forward bias should be applied to which junction?

A. collector-emitter B. base-emitter

C. collector-base D. cathode-anode

Answer: Option A

.

28. The input/output relationship of the common-collector and common-base amplifiers is:

A. 270 degrees

B. 180 degrees

C. 90 degrees

D. 0 degrees

Answer: Option D

.

29. If a transistor operates at the middle of the dc load line, a decrease in the current gain will move the Q point:

A. off the load line

B. nowhere

C. up

D. down

Answer: Option D

.

30. Which is the higher gain provided by a C-E configuration?


C. resistance D. power

Answer: Option D

31. What is the collector current for a C-E configuration with a beta of

100 and a base current of 30 A?

A. 30 A

B. .3 A

C. 3 mA

D. 3 MA

Answer: Option C

XXVI - Field Effect Transistors (FET)

1. Junction Field Effect Transistors (JFET) contain how many diodes?

A. 4 B. 3

C. 2 D. 1

Answer: Option D

.

2. When an input delta of 2 V produces a transconductance of 1.5 mS, what is the drain current delta?

A. 666 mA

B. 3 mA

C. 0.75 mA

D. 0.5 mA

Answer: Option B

.

3. When not in use, MOSFET pins are kept at the same potential through the use of:

A. shipping foil

B. nonconductive foam

C. conductive foam

D. a wrist strap

Answer: Option C

.

4. D-MOSFETs are sometimes used in series to construct a cascode high-frequency amplifier to overcome the loss of:

A. low output impedance

B. capacitive reactance

C. high input impedance

D. inductive reactance

Answer: Option C

.

5. A "U" shaped, opposite-polarity material built near a JFET-channel center is called the:

A. gate

B. block

C. drain

D. heat sink

Answer: Option A 6. When testing an n-channel D-MOSFET,

resistance G to D = , resistance G to S = , resistance D to SS = and

500 , depending on the polarity of the

ohmmeter, and resistance D to S =

500 . What is wrong?

A. short D to S

B. open G to D

C. open D to SS

D. nothing

Answer: Option D

.

7. In the constant-current region, how will the IDS change in an n-channel JFET?

A. As VGS decreases ID decreases.

B. As VGS increases ID increases.

C.

As VGS decreases ID remains

constant.

D.

As VGS increases ID remains constant.

Answer: Option A

.

8. A MOSFET has how many terminals?

A. 2 or 3

B. 3

C. 4

D. 3 or 4

Answer: Option D

.

9. IDSS can be defined as:

A.

the minimum possible drain

current

B. the maximum possible current

with VGS held at –4 V

C.

the maximum possible current with VGS held at 0 V

D.

the maximum drain current with the source shorted

Answer: Option C

.

10. What is the input impedance of a common-gate configured JFET?

A. very low

B. low

C. high

D. very high

Answer: Option A

11. JFET terminal "legs" are connections to the drain, the gate, and the:

A. channel B. source

C. substrate D. cathode

Answer: Option B

.

12. A very simple bias for a D-MOSFET is called:

A. self biasing

B. gate biasing

C. zero biasing

D. voltage-divider biasing

Answer: Option C

.

13. With the E-MOSFET, when gate input voltage is zero, drain current is:

A. at saturation

B. zero

C. IDSS

D. widening the channel

Answer: Option B

.

14. With a 30-volt VDD, and an 8-kilohm drain resistor, what is the E-MOSFET Q point voltage, with ID = 3 mA?

A. 6 V

B. 10 V

C. 24 V

D. 30 V

Answer: Option A

.

15. When an input signal reduces the channel size, the process is called:

A. enhancement

B. substrate connecting

C. gate charge

D. depletion

Answer: Option D

16. Which JFET configuration would connect a high-resistance signal source to a low-resistance load?

A. source follower

B. common-source

C. common-drain

D. common-gate

Answer: Option A

.

17. How will electrons flow through a p-channel JFET?

A. from source to drain

B. from source to gate

C. from drain to gate

D. from drain to source

Answer: Option D

.

18. When VGS = 0 V, a JFET is:

A. saturated

B. an analog device

C. an open switch

D. cut off

Answer: Option A

.

19. When applied input voltage varies the resistance of a channel, the result is called:

A. saturization

B. polarization

C. cutoff

D. field effect

Answer: Option D

.

20. When is a vertical channel E-MOSFET used?

A. for high frequencies

B. for high voltages

C. for high currents

D. for high resistances

Answer: Option C 21. When the JFET is no longer able to control the current,

this point is called the:

A. breakdown region

B. depletion region

C. saturation point

D. pinch-off region

Answer: Option A

.

22. With a JFET, a ratio of output current change against an input voltage change is called:

A. transconductance B. siemens

C. resistivity D. gain

Answer: Option A

.

23. Which type of JFET bias requires a negative supply voltage?

A. feedback

B. source

C. gate

D. voltage divider

Answer: Option C

.

24. How will a D-MOSFET input impedance change with signal frequency?

A.

As frequency increases input impedance

increases.

B.

As frequency increases input impedance is constant.

C.

As frequency decreases input impedance increases.

D.

As frequency decreases input impedance is constant.

Answer: Option C

.

25. The type of bias most often used with E-MOSFET circuits is:

A. constant current

B. drain-feedback

C. voltage-divider

D. zero biasing

Answer: Option B 26. The transconductance curve of a JFET is a graph of:

A. IS versus VDS

B. IC versus VCE

C. ID versus VGS

D. ID × RDS

Answer: Option C

.

27. The common-source JFET amplifier has:

A.

a very high input impedance and a relatively

low voltage gain

B.

a high input impedance and a very high voltage

gain

C. a high input impedance and a voltage gain less

than 1

D. no voltage gain

Answer: Option A

.

28.

Using voltage-divider biasing, what is the voltage at the gate VGS?

A. 5.2 V

B. 4.2 V

C. 3.2 V

D. 2.2 V

Answer: Option A

.

29. The overall input capacitance of a dual-gate D-MOSFET is lower because the devices are usually connected:

A. in parallel

B. with separate insulation

C. with separate inputs

D. in series

Answer: Option D

.

30. What is the transconductance of an FET when

ID = 1 mA and VGS = 1 V?

A. 1 kS

B. 1 mS

C. 1 k

D. 1 m

Answer: Option B In an n-channel JFET, what will happen at the

pinch-off voltage?

A.

the value of VDS at which further increases

in VDS will cause no further increase in ID

B.

the value of VGS at which further decreases

in VGS will cause no further increases in ID

C.

the value of VDG at which further decreases

in VDG will cause no further increases in ID

D.

the value of VDS at which further increases in VGS will cause no further increases in ID

Answer: Option A

31. Which component is considered to be an "OFF" device?

A. transistor B. JFET

C. D-MOSFET D. E-MOSFET

Answer: Option D

.

32. In an n-channel JFET, what will happen at the pinch-off voltage?

A.

the value of VDS at which further increases in VDS will cause no further increase in ID

B.

the value of VGS at which further decreases in VGS will cause no further increases in ID

C.

the value of VDG at which further decreases in VDG will cause no

further increases in ID

D.

the value of VDS at which further increases in VGS will cause no further increases in ID

Answer: Option A

XXVII - THYRISTORS AND TRANDUCERS

1. A TRIAC:

A. can trigger only on positive gate voltages

B. can trigger only on negative gate voltages

C. cannot be triggered with gate voltages

D.

can be triggered by either a positive or a negative gate voltage

Answer: Option D

.

2. When checking a good SCR or TRIAC with an ohmmeter it will:

A. show high resistance in both directions

B.

show low resistance with positive on anode and

negative on cathode, and high resistance when reversed

C.

show high resistance with negative on anode

and positive on cathode, and low resistance when reversed

D. show low resistance in both directions

Answer: Option A

.

3. What does a hall effect sensor sense?

A. temperature

B. moisture

C. magnetic fields

D. pressure

Answer: Option C

.

4. What causes the piezoelectric effect?

A. heat or dissimilar metals

B. pressure on a crystal

C. water running on iron

D. a magnetic field

Answer: Option B

.

5. Which is the DIAC?

A.

B.

C.

D.

Answer: Option A 6. A UJT has:

A. two base leads

B. one emitter lead

C.

two emitter leads and one base lead

D.

one emitter lead and two base

leads

Answer: Option D

.

7. The only way to close an SCR is with:

A.

a trigger input applied to the gate

B. forward breakover voltage

C. low-current dropout

D. valley voltage

Answer: Option B

.

8. What is an SCR?

A.

a PNPN thyristor with 3

terminals

B.

a PNPN thyristor with 4

terminals

C.

a PNP thyristor with 3 terminals

D.

an NPN thyristor with 3 terminals

Answer: Option A

.

9. The only way to close an SCR is with:

A.

a trigger input applied to the gate

B. forward breakover voltage


D. valley voltage

Answer: Option B

.

10. What type of application would use a photovoltaic cell?

A. an automobile horn

B. a TI 92 calculator

C. a magnetic field detector

D. a remote power source

Answer: Option D

11. Which is the seven-segment display?

A.

B.

C.

D.

Answer: Option A

.

12. The smallest amount of current that the cathode-anode can have, and still sustain conduction of an SCR is called the:

A. maximum forward current

B. maximum forward gate current

C. holding current

D. reverse gate leakage current

Answer: Option D

.

13. Once a DIAC is conducting, the only way to turn it off is with:

A. a positive gate voltage

B. a negative gate voltage


D. breakover

Answer: Option C

.

14. Which is the TRIAC?

A.

B.

C.

D.

Answer: Option D

.

15. The DIAC is a:

A. transistor

B. unidirectional device

C. three-layer device

D. bidirectional device

Answer: Option D 16. What type of application would use

an injection laser diode?

A. a 10BASE-T Ethernet

B. a liquid crystal display

C. a fiber optic transmission line

D. a good flashlight

Answer: Option C

.

17. The PUT (programmable unijunction transistor) is actually a type of:

A. UJT thyristor

B. FET device

C. TRIAC

D. SCR

Answer: Option A

.

18. A transducer's function is to:

A. transmit electrical energy

B. convert energy

C. produce mechanical energy

D. prevent current flow

Answer: Option B

XVIII - ANALOG TO DIGITAL

1. The two basic types of signals are analog and:

A. digilog

B. digital

C. vetilog

D. sine wave

Answer: Option B

.

2. Which of the following characterizes an analog quantity?

A. Discrete levels represent changes in a quantity.

B. Its values follow a logarithmic response curve.

C. It can be described with a finite number of steps.

D.

It has a continuous set of values over a given

range.

Answer: Option D

.

3. ASCII stands for:

A. American Serial Communication Interface

B. Additive Signal Coupling Interface

C.

American Standard Code for Information Interchange


Answer: Option C

.

4. Which type of signal is represented by discrete values?

A. noisy signal

B. nonlinear

C. analog

D. digital

Answer: Option D

.

5. A data conversion system may be used to interface a digital computer system to:

A. an analog output device

B. a digital output device

C. an analog input device

D. a digital printer

Answer: Option A

XXIX - NUMBER SYSTEMS AND CODES

1. Base 10 refers to which number system?

A. binary coded decimal

B. decimal

C. octal

D. hexadecimal

Answer: Option B

.

2. Convert the decimal number 151.75 to binary.

A. 10000111.11 B. 11010011.01

C. 00111100.00 D. 10010111.11

Answer: Option D

.

3. Convert the binary number 1011010 to hexadecimal.

A. 5B B. 5F

C. 5A D. 5C

Answer: Option C

.

4. The number of bits used to store a BCD digit is:

A. 8 B. 4

C. 1 D. 2

Answer: Option B

.

5. Sample-and-hold circuits in ADCs are designed to:

A. sample and hold the output of the binary counter during the conversion process

B. stabilize the ADCs threshold voltage during the conversion process

C. stabilize the input analog signal during the conversion process

D. sample and hold the ADC staircase waveform during the conversion process

Answer: Option C

6. The weight of the LSB as a binary

number is:

A. 1 B. 2

C. 3 D. 4

Answer: Option A

.

7. What is the difference between binary coding and binary coded decimal?

A. Binary coding is pure binary.

B. BCD is pure binary.

C. Binary coding has a decimal format.

D. BCD has no decimal format.

Answer: Option A

.

8. Convert the binary number 1001.0010 to decimal.

A. 125 B. 12.5

C. 90.125 D. 9.125

Answer: Option D

.

9. Convert 110010012 (binary) to decimal.

A. 201 B. 2001

C. 20 D. 210

Answer: Option A

.

10. What is the decimal value of the hexadecimal number 777?

A. 191 B. 1911

C. 19 D. 19111

Answer: Option B 11. What is the resultant binary of the decimal problem 49

+ 1 = ?

A. 01010101 B. 00110101

C. 00110010 D. 00110001

Answer: Option C

.

12. 3428 is the decimal value for which of the following binary coded decimal (BCD) groupings?

A. 11010001001000 B. 11010000101000

C. 011010010000010 D. 110100001101010

Answer: Option B

.

13. What is the result when a decimal 5238 is converted to base 16?

A. 327.375 B. 12166

C. 1388 D. 1476

Answer: Option D

XXX - LOGIC GATES

1. The output will be a LOW for any case when one or more inputs are zero in a(n):

A. OR gate

B. NOT gate

C. AND gate

D. NAND gate

Answer: Option C

.

2. If a signal passing through a gate is inhibited by sending a low into one of the inputs, and the output is HIGH, the gate is a(n):

A. AND B. NAND

C. NOR D. OR

Answer: Option B

.

3. A single transistor can be used to build which of the following digital logic gates?

A. AND gates

B. OR gates

C. NOT gates

D. NAND gates

Answer: Option C

.

4. The logic gate that will have HIGH or "1" at its output when any one of its inputs is HIGH is a(n):

A. OR gate

B. AND gate

C. NOR gate

D. NOT gate

Answer: Option A

.

5. How many NAND circuits are contained in a 7400 NAND IC?

A. 1 B. 2

C. 4 D. 8

Answer: Option C

6. Exclusive-OR (XOR) logic gates can be constructed from what other logic gates?

A. OR gates only

B. AND gates and NOT gates

C. AND gates, OR gates, and NOT gates

D. OR gates and NOT gates

Answer: Option C

.

7. How many truth table entries are necessary for a four-input circuit?

A. 4 B. 8

C. 12 D. 16

Answer: Option D

.

8. A NAND gate has:

A. LOW inputs and a LOW output

B. HIGH inputs and a HIGH output

C. LOW inputs and a HIGH output

D. None of the these

Answer: Option C

.

9. The basic logic gate whose output is the complement of the input is the:

A. OR gate

B. AND gate

C. INVERTER gate

D. comparator

Answer: Option C

.

10. What input values will cause an AND logic gate to produce a HIGH output?

A. At least one input is HIGH.

B. At least one input is LOW.

C. All inputs are HIGH.

D. All inputs are LOW.

Answer: Option C

XXXI - LOGIC CIRCUIT SIMPLIFICATION

1. Which statement below best describes a Karnaugh map?

A. It is simply a rearranged truth table.

B.

The Karnaugh map eliminates the need for using NAND and NOR gates.

C.

Variable complements can be eliminated by using Karnaugh maps.

D.

A Karnaugh map can be used to replace Boolean rules.

Answer: Option A

.

2. Which of the examples below expresses the commutative law of multiplication?

A. A + B = B + A

B. A • B = B + A

C. A • (B • C) = (A • B) • C

D. A • B = B • A

Answer: Option D

.

3. The Boolean expression is logically

equivalent to what single gate?

A. NAND B. NOR

C. AND D. OR

Answer: Option A

.

4. The observation that a bubbled input OR gate is interchangeable with a bubbled output AND gate is referred to as:

A. a Karnaugh map

B. DeMorgan's second theorem

C. the commutative law of addition

D. the associative law of multiplication

Answer: Option B

.

5. The systematic reduction of logic circuits is accomplished by:

A. symbolic reduction

B. TTL logic

C. using Boolean algebra

D. using a truth table

Answer: Option C

6. Logically, the output of a NOR gate would have the same Boolean expression as a(n):

A.

NAND gate immediately followed by an

INVERTER

B.

OR gate immediately followed by an

INVERTER

C.

AND gate immediately followed by an INVERTER

D.

NOR gate immediately followed by an INVERTER

Answer: Option B

.

7. Which of the examples below expresses the distributive law of Boolean algebra?

A. A • (B • C) = (A • B) + C

B. A + (B + C) = (A • B) + (A • C)

C. A • (B + C) = (A • B) + (A • C)

D. (A + B) + C = A + (B + C)

Answer: Option C

.

8. Which output expression might indicate a product-of-sums circuit construction?

A.

B.

C.

D.

Answer: Option D

.

9. One of DeMorgan's theorems states

that . Simply stated, this

means that logically there is no difference between:

A.

a NAND gate and an AND gate with a

bubbled output

B.

a NOR gate and an AND gate with a

bubbled output

C.

a NOR gate and a NAND gate with a

bubbled output

D.

a NAND gate and an OR gate with a bubbled output

Answer: Option A

.

10. The commutative law of addition and multiplication indicates that:

A.

the way we OR or AND two variables is

unimportant because the result is the same

B.

we can group variables in an AND or in an OR any way we want

C.

an expression can be expanded by multiplying term by term just the same as in ordinary algebra

D.

the factoring of Boolean expressions requires the multiplication of product terms that contain like variables

Answer: Option A

11.

Which of the following expressions is in the sum-of-products (SOP) form?

A. Y = (A + B)(C + D)

B. Y = AB(CD)

C.

D.

Answer: Option C

XXXII - STANDARD LOGIC DEVICES (SLD)

1. A digital logic device used as a buffer should have what input/output characteristics?

A.

high input impedance and high output

impedance

B.

low input impedance and high output

impedance

C.

low input impedance and low output impedance

D.

high input impedance and low output impedance

Answer: Option D

.

2. What is the standard TTL noise margin?

A. 5.0 V

B. 0.2 V

C. 0.8 V

D. 0.4 V

Answer: Option D

.

3. The range of a valid LOW input is:

A. 0.0 V to 0.4 V

B. 0.4 V to 0.8 V

C. 0.4 V to 1.8 V

D. 0.4 V to 2.4 V

Answer: Option B

.

4. When an IC has two rows of parallel connecting pins, the device is referred to as:

A. a QFP

B. a DIP

C. a phase splitter

D. CMOS

Answer: Option B

.

5. Which digital IC package type makes the most efficient use of printed circuit board space?

A. SMT

B. TO can

C. flat pack

D. DIP

Answer: Option A 6. The problem of interfacing IC logic

families that have different supply voltages (VCCs) can be solved by using a:

A. level-shifter

B. tri-state shifter

C. translator

D. level-shifter or translator

Answer: Option D

.

7. Ten TTL loads per TTL driver is known as:

A. noise immunity

B. power dissipation

C. fanout

D. propagation delay

Answer: Option C

.

8. Which of the following summarizes the important features of emitter-coupled logic (ECL)?

A.

negative voltage operation, high speed, and high power consumption

B.

good noise immunity, negative logic, high frequency capability, low power dissipation, and short propagation time

C.

slow propagation time, high frequency response, low power consumption, and high output voltage swings

D.

poor noise immunity, positive

supply voltage operation, good low-frequency operation, and low power

Answer: Option A

.

9. What quantities must be compatible when interfacing two different logic families?

A. only the currents

B.

both the voltages and the currents

C. only the voltages

D.

both the power dissipation and the impedance

Answer: Option B

.

10. CMOS logic is probably the best all-around circuitry because of its:

A. packing density

B. low power consumption

C. very high noise immunity

D.

low power consumption and

very high noise immunity

Answer: Option D

11. Low power consumption achieved by CMOS circuits is due to which construction characteristic?

A. complementary pairs

B. connecting pads

C. DIP packages

D. small-scale integration

Answer: Option A

.

12. A TTL totem pole circuit is designed so that the output transistors are:

A. always on together

B. providing phase splitting

C. providing voltage regulation

D. never on together

Answer: Option D

.

13. The time needed for an output to change as the result

of an input change is known as:

A. noise immunity

B. fanout

C. propagation delay

D. rise time

Answer: Option C

XXXIII - PROGRAMMABLE LOGIC DEVICES (PLD)

1. Which type of PLD should be used to program basic logic functions?

A. PLA B. PAL

C. CPLD D. SLD

Answer: Option B

.

2. The content of a simple programmable logic device (PLD) consists of:

A. fuse-link arrays

B. thousands of basic logic gates

C. advanced sequential logic functions

D.

thousands of basic logic gates and advanced

sequential logic functions

Answer: Option D

.

3. Once a PAL has been programmed:

A. it cannot be reprogrammed.

B. its outputs are only active HIGHs

C. its outputs are only active LOWs

D. its logic capacity is lost

Answer: Option A

.

4. The complex programmable logic device (CPLD) contains several PLD blocks and:

A. field-programmable switches

B. AND/OR arrays

C. a global interconnection matrix

D. a language compiler

Answer: Option C

.

5. PLAs, CPLDs, and FPGAs are all which type of device?

A. SLD B. PLD

C. EPROM D. SRAM

Answer: Option B

6. The difference between a PLA and a PAL is:

A.

the PLA has a programmable OR plane and a

programmable AND plane, while the PAL only has a programmable AND plane

B.

the PAL has a programmable OR plane and a

programmable AND plane, while the PLA only has a programmable AND plane

C.

the PAL has more possible product terms than the PLA

D. PALs and PLAs are the same thing.

Answer: Option A

XXXIV - TESTING AND TROUBLESHOOTING

1. A series of gradually decreasing sine wave oscillations is called:

A. ringing B. slew

C. overshooting D. undershooting

Answer: Option A

.

2. The determination of a digital signal's frequency and waveshape is best accomplished with which test equipment?

A. an oscilloscope

B. a multimeter

C. a spectrum analyzer

D. a frequency generator

Answer: Option A

.

3. A logic probe is placed on the output of a gate and the display indicator is dim. A logic pulser is used on each of the input terminals, but the output indication does not change. What is wrong?

A.

The dim indication on the logic probe indicates that the supply voltage is probably low.

B. The output of the gate appears to be open.

C.

The LOW indication is the result of a bad ground connection on the logic probe.

D. The gate is a tri-state device.

Answer: Option B

.

4. A +5 V PCB power source that has been "pulled down" to a +3.4 V level may be due to:

A. a circuit open

B. a faulty regulator

C. the half-split method

D. a circuit short

Answer: Option D

.

5. Measurement of pulse width should be taken at a 50% mean of the:

A. overshoot and undershoot

B. rise and fall

C. damping and ringing

D. leading and trailing amplitude

Answer: Option B

6. Which test equipment best allows a comparison between input and output signals?

A. an oscilloscope

B. a logic probe

C. a spectrum analyzer

D. a multitrace oscilloscope

Answer: Option D

.

7. The duty cycle of a pulse is determined by which formula?

A.

Duty Cycle =

B.

Duty Cycle =

C.

Duty Cycle =

D.

Duty Cycle =

Answer: Option A

.

8. What is the next step after discovering a faulty gate within an IC?

A. repair the gate

B. resolder the tracks

C. replace the IC involved

D. recheck the power source

Answer: Option C

.

9. The use of a multimeter with digital circuits allows the measurement of:

A. pulse width

B. voltage or resistance

C. current

D. pulse trains

Answer: Option B

.

10. The use of triggered sweep when using an oscilloscope provides more accuracy in which area?

A. frequency

B. amplitude

C. graticule activity

D. timing

Answer: Option D

11. The time needed for a pulse to increase from 10% to 90% of its amplitude defines:

A. pulse width

B. propagation delay

C. rise time

D. duty cycle

Answer: Option C

.

12. Which device would best aid in shorted track detection?

A. multimeter

B. current tracer

C. logic pulser

D. oscilloscope

Answer: Option B

XXXV - COMBINATIONAL LOGIC CIRCUITS

1. How many inputs are required for a 1-of-10 BCD decoder?

A. 4 B. 8

C. 10 D. 1

Answer: Option A

.

2. Most demultiplexers facilitate which of the following?

A. decimal to hexadecimal

B. single input, multiple outputs

C. ac to dc

D. odd parity to even parity

Answer: Option B

.

3. One application of a digital multiplexer is to facilitate:

A. code conversion

B. parity checking

C. parallel-to-serial data conversion

D. data generation

Answer: Option C

.

4. Select one of the following statements that best describes the parity method of error detection:

A.

Parity checking is best suited for detecting single-bit errors in transmitted codes.

B.

Parity checking is best suited for detecting double-bit errors that occur during the transmission of codes from one location to another.

C.

Parity checking is not suitable for detecting single-bit errors in transmitted codes.

D.

Parity checking is capable of detecting and correcting errors in transmitted codes.

Answer: Option A

.

5. A multiplexed display:

A.

accepts data inputs from one line and passes this data to multiple output lines

B.

uses one display to present two or more pieces of information

C.

accepts data inputs from multiple

lines and passes this data to multiple output lines

D.

accepts data inputs from several lines

and multiplexes this input data to four BCD lines

Answer: Option B

6. When two or more inputs are active simultaneously, the process is called:

A. first-in, first-out processing

B. priority encoding

C. ripple blanking

D. priority decoding

Answer: Option B

.

7. Which type of decoder will select one of sixteen outputs, depending on the 4-bit binary input value?

A. hexadecimal

B. dual octal outputs

C. binary-to-hexadecimal

D. hexadecimal-to-binary

Answer: Option A

.

8. A magnitude comparator determines:

A. A B and if A B or A >> B

B. A B and if A > B or A < b

C. A = B and if A > B or A < b

D. A B and if A < b or a > B

Answer: Option C

.

9. A circuit that responds to a specific set of signals to produce a related digital signal output is called a(n):

A. BCD matrix

B. display driver

C. encoder

D. decoder

Answer: Option C

.

10. Which digital system translates coded characters into a more intelligible form?

A. encoder B. display

C. counter D. decoder

Answer: Option D

11. A basic multiplexer principle can be demonstrated through the use of a:

A. single-pole relay

B. DPDT switch

C. rotary switch

D. linear stepper

Answer: Option C

.

12. In a BCD-to-seven-segment converter, why must a

code converter be utilized?

A. No conversion is necessary.

B. to convert the 4-bit BCD into gray code

C. to convert the 4-bit BCD into 10-bit code

D. to convert the 4-bit BCD into 7-bit code

Answer: Option D

XXXVI - FLIP-FLOPS AND TIMERS

1. Which of the following is correct for a gated D-type flip-flop?

A.

The Q output is either SET or RESET as soon as

the D input goes HIGH or LOW.

B.

The output complement follows the input when enabled.

C. Only one of the inputs can be HIGH at a time.

D.

The output toggles if one of the inputs is held HIGH.

Answer: Option A

.

2. When both inputs of a J-K flip-flop cycle, the output will:

A. be invalid

B. not change

C. change

D. toggle

Answer: Option B

.

3. Latches constructed with NOR and NAND gates tend to remain in the latched condition due to which configuration feature?

A. asynchronous operation

B. low input voltages

C. gate impedance

D. cross coupling

Answer: Option D

.

4. The 555 timer can be used in which of the following configurations?

A. astable, monostable

B. monostable, bistable

C. astable, toggled

D. bistable, tristable

Answer: Option A

.

5. A basic S-R flip-flop can be constructed by cross-coupling which basic logic gates?

A. AND or OR gates

B. XOR or XNOR gates

C. NOR or NAND gates

D. AND or NOR gates

Answer: Option C 6. One example of the use of an S-R flip-flop is as a(n):

A. transition pulse generator

B. astable oscillator

C. racer

D. switch debouncer

Answer: Option D

.

7. If both inputs of an S-R NAND latch are LOW, what will

happen to the output?

A. The output would become unpredictable.

B. The output will toggle.

C. The output will reset.

D. No change will occur in the output.

Answer: Option A

.

8. The equation for the output frequency of a 555 timer operating in the astable mode

is: .

What value of C1 will be required if R1 = 1 k , R2 = 1 k

, and f = 1 kHz?

A. 0.33 F

B. 0.48 F

C. 480 F

D. 33 nF

Answer: Option B

.

9. An astable multivibrator is a circuit that:

A. has two stable states

B. is free-running

C. produces a continuous output signal

D.

is free-running and produces a continuous output signal

Answer: Option C

.

10. What is another name for a one-shot?

A. monostable B. bistable

C. astable D. tristable

Answer: Option A 11. The truth table for an S-R flip-flop has how many

VALID entries?

A. 3 B. 1

C. 4 D. 2

Answer: Option A

.

12. What is the significance of the J and K terminals on the J-K flip-flop?

A.

There is no known significance in their

designations.

B.

The J represents "jump," which is how the Q

output reacts whenever the clock goes HIGH and the J input is also HIGH.

C.

The letters represent the initials of Johnson and

King, the co-inventors of the J-K flip-flop.

D.

All of the other letters of the alphabet are already in use.

Answer: Option A

.

13. Which of the following describes the operation of a positive edge-triggered D-type flip-flop?

A. If both inputs are HIGH, the output will toggle.

B.

The output will follow the input on the leading edge of the clock.

C.

When both inputs are LOW, an invalid state exists.

D.

The input is toggled into the flip-flop on the leading edge of the clock and is passed to the output on the trailing edge of the clock.

Answer: Option B

.

14. What is one disadvantage of an S-R flip-flop?

A. It has no Enable input.

B. It has a RACE condition.

C. It has no clock input.

D. It has only a single output.

Answer: Option B

XXXVII - SEQUENTIAL LOGIC CIRCUITS

1. A ripple counter's speed is limited by the propagation delay of:

A. each flip-flop

B. all flip-flops and gates

C. the flip-flops only with gates

D. only circuit gates

Answer: Option A

.

2. To operate correctly, starting a ring counter requires:

A. clearing all the flip-flops

B.

presetting one flip-flop and clearing all the

others

C.

clearing one flip-flop and presetting all the

others

D. presetting all the flip-flops

Answer: Option B

.

3. What type of register would shift a complete binary

number in one bit at a time and shift all the stored bits out one bit at a time?

A. PIPO B. SISO

C. SIPO D. PISO

Answer: Option B

.

4. Synchronous counters eliminate the delay problems encountered with asynchronous (ripple) counters because the:

A.

input clock pulses are applied only to the first and last stages

B.

input clock pulses are applied only to the last stage

C.

input clock pulses are not used to activate any of the counter stages

D.

input clock pulses are applied simultaneously to each stage

Answer: Option D

.

5. One of the major drawbacks to the use of asynchronous counters is that:

A.

low-frequency applications are limited because

of internal propagation delays

B.

high-frequency applications are limited because

of internal propagation delays

C.

Asynchronous counters do not have major drawbacks and are suitable for use in high- and

low-frequency counting applications.

D.

Asynchronous counters do not have propagation delays, which limits their use in high-frequency applications.

Answer: Option B 6. Which type of device may be used to interface a parallel

data format with external equipment's serial format?

A. key matrix

B. UART

C. memory chip

D. serial-in, parallel-out

Answer: Option B

.

7. When the output of a tri-state shift register is disabled, the output level is placed in a:

A. float state

B. LOW state

C. high impedance state

D. float state and a high impedance state

Answer: Option D

.

8. A comparison between ring and johnson counters indicates that:

A.

a ring counter has fewer flip-flops but requires more decoding circuitry

B. a ring counter has an inverted feedback path

C.

a johnson counter has more flip-flops but less

decoding circuitry

D. a johnson counter has an inverted feedback path

Answer: Option D

.

9. A sequence of equally spaced timing pulses may be easily generated by which type of counter circuit?

A. shift register sequencer

B. clock

C. johnson

D. binary

Answer: Option A

.

10. What is meant by parallel-loading the register?

A. Shifting the data in all flip-flops simultaneously

B. Loading data in two of the flip-flops

C.

Loading data in all four flip-flops at the same

time

D.

Momentarily disabling the synchronous SET and

RESET inputs

Answer: Option C 11. What is a shift register that will accept a parallel input

and can shift data left or right called?

A. tri-state

B. end around

C. bidirectional universal

D. conversion

Answer: Option C

.

12. What happens to the parallel output word in an asynchronous binary down counter whenever a clock pulse occurs?

A. The output word decreases by 1.

B. The output word decreases by 2.

C. The output word increases by 1.

D. The output word increases by 2.

Answer: Option A

.

13. Mod-6 and mod-12 counters are most commonly used in:

A. frequency counters

B. multiplexed displays

C. digital clocks

D. power consumption meters

Answer: Option C

XXXVIII - ARITHMETIC OPERATIONS AND CIRCUITS

1. When 1100010 is divided by 0101, what will be the decimal remainder?

A. 2 B. 3

C. 4 D. 6

Answer: Option B

.

2. What are the two types of basic adder circuits?

A. half adder and full adder

B. half adder and parallel adder

C. asynchronous and synchronous

D. one's complement and two's complement

Answer: Option A

.

3. Adding the two's complement of –11 + (–2) will yield which two's complement answer?

A. 1110 1101

B. 1111 1001

C. 1111 0011

D. 1110 1001

Answer: Option C

.

4. The two's complement system is to be used to add the signed numbers 11110010 and 11110011. Determine, in decimal, the sign and value of each number and their sum.

A. –14 and –13; –27

B. –113 and –114; 227

C. –27 and –13; 40

D. –11 and –16; –27

Answer: Option A

.

5. The fast carry or look-ahead carry circuits found in most 4-bit parallel-adder circuits:

A. increase ripple delay

B. add a 1 to complemented inputs

C. reduce propagation delay

D. determine sign and magnitude

Answer: Option C

6. How many basic binary subtraction operations are possible?

A. 4 B. 3

C. 2 D. 1

Answer: Option D

.

7. How many basic binary subtraction combinations are possible?

A. 4 B. 3

C. 2 D. 1

Answer: Option A

.

8. Use the two's complement system to add the signed numbers 11110010 and 11110011. Determine, in decimal, the sign and value of each number and their sum.

A. –14 and –13; –27

B. –113 and –114; 227

C. –27 and –13; 40

D. –11 and –16; –27

Answer: Option A

.

9. The selector inputs to an arithmetic-logic unit (ALU) determine the:

A. selection of the IC

B. arithmetic or logic function

C. data word selection

D. clock frequency to be used

Answer: Option B

.

10. Adding in binary, the decimal values 26 + 27 will produce a sum of:

A. 111010 B. 110110

C. 110101 D. 101011

Answer: Option C 11. Binary subtraction of a decimal 15 from 43 will utilize

which two's complement?

A. 101011 B. 110000

C. 011100 D. 110001

Answer: Option D

.

12. When multiplying in binary the decimal values 13 × 11, what is the third partial product?

A. 100000 B. 100001

C. 0000 D. 1011

Answer: Option A

.

13. The range of an 8-bit two's complement word is from:

A. +12810 to –12810

B. –12810 to +12710

C. +12810 to –12710

D. +12710 to –12710

Answer: Option B

XXXIX - SEMICONDUCTOR MEMORY

1. A computerized self-diagnostic for a ROM test uses:

A. the check-sum method

B. a ROM listing

C. ROM comparisons

D. a checkerboard test

Answer: Option A

.

2. How many storage locations are available when a memory device has twelve address lines?

A. 144 B. 512

C. 2048 D. 4096

Answer: Option D

.

3. Which of the following memories uses a MOSFET and a capacitor as its memory cell?

A. SRAM B. DRAM

C. ROM D. DROM

Answer: Option B

.

4. Which of the following best describes nonvolatile memory?

A.

memory that retains stored information when electrical power is removed

B.

memory that loses stored information when

electrical power is removed

C. magnetic memory

D. nonmagnetic memory

Answer: Option A

.

5. The access time (tacc) of a memory IC is governed by the IC's:

A. internal address buffer

B. internal address decoder

C. volatility

D. internal address decoder and volatility

Answer: Option B

6. Select the best of read-only memory (ROM).

A.

nonvolatile, used to store information that

changes during system operation

B.

nonvolatile, used to store information that does not change during system operation

C.

volatile, used to store information that changes during system operation

D.

volatile, used to store information that does not change during system operation

Answer: Option B

.

7. Advantage(s) of an EEPROM over an EPROM is (are):

A.

the EPROM can be erased with ultraviolet light in much less time than an EEPROM

B.

the EEPROM can be erased and reprogrammed without removal from the circuit

C.

the EEPROM has the ability to erase and

reprogram individual words

D.

the EEPROM can erase and reprogram individual

words without removal from the circuit

Answer: Option D

.

8. Which of the following RAM timing parameters

determine(s) its operating speed?

A. tacc

B. taa and tacs

C. t1 and t3

D. trc and twc

Answer: Option C

.

9. Memory that loses its contents when power is lost is:

A. nonvolatile B. volatile

C. random D. static

Answer: Option B

.

10. Select the best of the fusible-link PROM.

A. user programmable, one-time programmable

B.

manufacturer programmable, one-time programmable

C. user programmable, reprogrammable

D. manufacturer programmable, reprogrammable

Answer: Option A

11. A nonvolatile type of memory that can be programmed and erased in sectors, rather than one byte at a time is:

A. flash memory

B. EPROM

C. EEPROM

D. MPROM

Answer: Option A

.

12. Which of the following best describes static memory devices?

A.

memory devices that are magnetic in nature and do not require constant refreshing

B.

semiconductor memory devices in which stored

data is retained as long as power is applied

C.

memory devices that are magnetic in nature

and require constant refreshing

D.

semiconductor memory devices in which stored

data will not be retained with the power applied unless constantly refreshed

Answer: Option B

.

13. What is the principal advantage of using address multiplexing with DRAM memory?

A. reduced memory access time

B.

reduced requirement for constant refreshing of

the memory contents

C. reduced pin count and decrease in package size

D.

no requirement for a chip-select input line,

thereby reducing the pin count

Answer: Option C

XXXX - ANALOG AND DIGITAL CONVERTERS

1. Which of the following is a type of error associated with digital-to-analog converters (DACs)?

A. nonmonotonic error

B. incorrect output codes

C. offset error

D. nonmonotonic and offset error

Answer: Option D

.

2. A 4-bit R/2R digital-to-analog (DAC) converter has a reference of 5 volts. What is the analog output for the input code 0101.

A. 0.3125 V

B. 3.125 V

C. 0.78125 V

D. –3.125 V

Answer: Option B

.

3. A binary-weighted digital-to-analog converter has an

input resistor of 100 k . If the resistor is connected to

a 5 V source, the current through the resistor is:

A. 50 A

B. 5 mA

C. 500 A

D. 50 mA

Answer: Option A

.

4. What is the resolution of a digital-to-analog converter (DAC)?

A.

It is the comparison between the actual output

of the converter and its expected output.

B.

It is the deviation between the ideal straight-line output and the actual output of the converter.

C.

It is the smallest analog output change that can occur as a result of an increment in the digital input.

D.

It is its ability to resolve between forward and reverse steps when sequenced over its entire range.

Answer: Option C

.

5. The practical use of binary-weighted digital-to-analog converters is limited to:

A. R/2R ladder D/A converters

B. 4-bit D/A converters

C. 8-bit D/A converters

D. op-amp comparators

Answer: Option B 6. The difference between analog voltage represented by

two adjacent digital codes, or the analog step size, is the:

A. quantization B. accuracy

C. resolution D. monotonicity

Answer: Option C

.

7. The primary disadvantage of the flash analog-to digital converter (ADC) is that:

A.

it requires the input voltage to be applied to the inputs simultaneously

B. a long conversion time is required

C.

a large number of output lines is required to

simultaneously decode the input voltage

D.

a large number of comparators is required to

represent a reasonable sized binary number

Answer: Option D

.

8. A binary-weighted digital-to-analog converter has a

feedback resistor, Rf, of 12 k . If 50 A of current is

through the resistor, the voltage out of the circuit is:

A. 0.6 V

B. –0.6 V

C. 0.1 V

D. –0.1 V

Answer: Option B

.

9. What is the major advantage of the R/2R ladder digital-to-analog (DAC), as compared to a binary-weighted digital-to-analog DAC converter?

A. It only uses two different resistor values.

B.

It has fewer parts for the same number of

inputs.

C. Its operation is much easier to analyze.

D.

The virtual ground is eliminated and the circuit is therefore easier to understand and troubleshoot.

Answer: Option A

.

10. The resolution of a 0–5 V 6-bit digital-to-analog converter (DAC) is:

A. 63% B. 64%

C. 1.56% D. 15.6%

Answer: Option C 11. In a flash analog-to-digital converter, the output of

each comparator is connected to an input of a:

A. decoder

B. priority encoder

C. multiplexer

D. demultiplexer

Answer: Option B

.

12. Which is not an analog-to-digital (ADC) conversion error?

A. differential nonlinearity

B. missing code

C. incorrect code

D. offset

Answer: Option A

.

13. Sample-and-hold circuits in analog-to digital converters (ADCs) are designed to:

A.

sample and hold the output of the binary counter during the conversion process

B.

stabilize the comparator's threshold voltage

during the conversion process

C.

stabilize the input analog signal during the conversion process

D.

sample and hold the D/A converter staircase waveform during the conversion process

Answer: Option C

XXXXI - COMPUTER HARDWARE AND SOFTWARE

1. When referring to instruction words, a mnemonic is:

A. a short abbreviation for the operand address

B.

a short abbreviation for the operation to be

performed

C.

a short abbreviation for the data word stored at the operand address

D. shorthand for machine language

Answer: Option B

.

2. What is the difference between mnemonic codes and machine codes?

A. There is no difference.

B.

Machine codes are in binary, mnemonic codes are in shorthand English.

C.

Machine codes are in shorthand English, mnemonic codes are in binary.

D.

Machine codes are in shorthand English,

mnemonic codes are a high-level language.

Answer: Option B

.

3. Which bus is bidirectional?

A. data bus

B. control bus

C. address bus

D. multiplexed bus

Answer: Option A

.

4. The software used to drive microprocessor-based systems is called:

A. assembly language programs

B. firmware

C. BASIC interpreter instructions

D. flowchart instructions

Answer: Option A

.

5. A microprocessor unit, a memory unit, and an input/output unit form a:

A. CPU B. compiler

C. microcomputer D. ALU

Answer: Option C 6. How many buses are connected as part of the 8085

microprocessor?

A. 2 B. 3

C. 5 D. 8

Answer: Option B

.

7. Which of the following is not a computer bus?

A. data bus

B. timer bus

C. control bus

D. address bus

Answer: Option B

.

8. The technique of assigning a memory address to each I/O device in the SAM system is called:

A. wired I/O

B. I/O mapping

C. dedicated I/O

D. memory-mapped I/O

Answer: Option D

.

9. How many bits are used in the data bus?

A. 7 B. 8

C. 9 D. 16

Answer: Option B

.

10. A port can be:

A. strictly for input

B. strictly for output

C. bidirectional

D. all the above

Answer: Option C

11. Which of the following is not a basic element within the microprocessor?

A. microcontroller

B. arithmetic-logic unit (ALU)

C. temporary register

D. accumulator

Answer: Option A

.

12. How many bits are used in the address bus?

A. 7 B. 8

C. 9 D. 16

Answer: Option D

.

13. Exceptions to the 8085 microprocessor normal operation are called:

A. jump instructions

B. decoding

C. interrupts

D. jump instructions or interrupts

Answer: Option D

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