An ideal voltage source hasa. Zero internal resistanceb. Infinite internal resistancec. A load-dependent voltaged. A load-dependent current

A real voltage source hasa. Zero internal resistanceb. Infinite internal resistancec. A small internal resistanced. A large internal resistance

If a load resistance is 1k ohm, a stiff voltage source has a resistance ofa. At least 10 ohmb. Less than 10 ohmc. More than 100 kohmd. Less than 100 kohm

An ideal current source hasa. Zero internal resistanceb. Infinite internal resistancec. A load-dependent voltaged. A load-dependent current

A real current source hasa. Zero internal resistanceb. Infinite internal resistancec. A small internal resistanced. A large internal resistance

If a load resistance is 1 kohm, a stiff current source has a resistance ofa. At least 10 ohmb. Less than 10 ohmc. More than 100 kohmd. Less than 100 kohm

The Thevenin voltage is the same as thea. Shorted-load voltageb. Open-load voltagec. Ideal source voltaged. Norton voltage

The Thevenin resistance is equal in value to thea. Load resistanceb. Half the load resistancec. Internal resistance of a Norton circuitd. Open-load resistance

To get the Thevenin voltage, you have toa. Short the load resistorb. Open the load resistorc. Short the voltage sourced. Open the voltage source

To get the Norton current, you have toa. Short the load resistorb. Open the load resistorc. Short the voltage sourced. Open the current source

The Norton current is sometimes called thea. Shorted-load currentb. Open-load currentc. Thevenin currentd. Thevenin voltage

A solder bridge a. may produce a shortb. may cause an openc. is useful in some circuitsd. always has high resistance

A cold-solder joint a. shows good soldering techniqueb. usually produces an openc. is sometimes usefuld. always has low resistance

An open resistor hasa. Infinite current through itb. Zero voltage across itc. Infinite voltage across itd. Zero current through it

A shorted resistor hasa. Infinite current through itb. Zero voltage across itc. Infinite voltage across itd. Zero current through it

An ideal voltage source and an internal resistance is an example of thea. Ideal approximationb. Second approximationc. Higher approximationd. Exact model

Treating a connecting wire as a conductor with zero resistance is an example of thea. Ideal approximationb. Second approximationc. Higher approximationd. Exact model

The voltage out of an ideal voltage sourcea. Is zerob. Is constantc. Depends on the value of load resistanced. Depends on the internal resistance

The current out of an ideal current sourcea. Is zerob. Is constantc. Depends on the value of load resistanced. Depends on the internal resistance

Thevenin’s theorem replaces a complicated circuit facing a load by ana. Ideal voltage source and parallel resistorb. Ideal current source and parallel resistorc. Ideal voltage source and series resistord. Ideal current source and series resistor

Norton’s theorem replaces a complicated circuit facing a load by ana. Ideal voltage source and parallel resistorb. Ideal current source and parallel resistorc. Ideal voltage source and series resistord. Ideal current source and series resistor

One way to short a device isa. With a cold-solder jointb. With a solder bridgec. By disconnecting itd. By opening itDerivations are a. Discoveriesb. Inventionsc. Produced by mathematicsd. Always called theorems

Laws are proved bya. Definitionb. Experimentc. Mathematicsd. Formulas

Definitions area. Man made b. Inventedc. Made upd. All of the above

The nucleus of a copper atom contains how many protons? a. 1b. 4c. 18d. 29

The net charge of a neutral copper atom isa. 0b. +1c. -1d. +4

Assume the valence electron is removed from a copper atom. The net charge of the atom becomesa. 0b. + 1c. -1d. +4

The valence electron of a copper atom experiences what kind of attraction toward the nucleus?a. Noneb. Weakc. Strongd. Impossible to say

How many valence electrons does a silicon atom have?a. 0b. 1c. 2d. 4

Which is the most widely used semiconductor?a. Copperb. Germaniumc. Silicond. None of the above

How many protons does the nucleus of a silicon atom contain?a. 4b. 14c. 29d. 32

Silicon atoms combine into an orderly pattern called aa. Covalent bondb. Crystalc. Semiconductord. Valence orbit

An intrinsic semiconductor has some holes in it at room temperature. What causes these holes?a. Dopingb. Free electronsc. Thermal energyd. Valence electrons

Each valence electron in an intrinsic semiconductor establishes aa. Covalent bondb. Free electronc. Holed. Recombination

The merging of a free electron and a hole is calleda. Covalent bondingb. Lifetimec. Recombinationd. Thermal energy

At room temperature an intrinsic silicon crystal acts approximately likea. A batteryb. A conductorc. An insulatord. A piece of copper wire

The amount of time between the creation of a hole and its disappearance is calleda. Dopingb. Lifetimec. Recombinationd. Valence

The valence electron of a conductor is also called a

a. Bound electronb. Free electronc. Nucleusd. Proton

A conductor has how many types of flow?a. 1b, 2c. 3d. 4

A semiconductor has how many types of flow?a. 1b. 2c. 3d. 4

When a voltage is applied to a semiconductor, holes will flowa. Away from the negative potentialb. Toward the positive potentialc. In the external circuitd. None of the above

A conductor has how many holes?a. Manyb. Nonec. Only those produced by thermal energyd. The same number as free electrons

In an intrinsic semiconductor, the number of free electronsa. Equals the number of holesb. Is greater than the number of holesc. Is less than the number of holesd. None of the above

Absolute zero temperature equalsa. -273 degrees Cb. 0 degrees Cc. 25 degrees Cd. 50 degrees C

At absolute zero temperature an intrinsic semiconductor hasa. A few free electronsb. Many holesc. Many free electronsd. No holes or free electrons

At room temperature an intrinsic semiconductor hasa. A few free electrons and holesb. Many holesc. Many free electronsd. No holes

The number of free electrons and holes in an intrinsic semiconductor increases when the temperaturea. Decreasesb. Increasesc. Stays the samed. None of the above

The flow of valence electrons to the left means that holes are flowing to thea. Leftb. Rightc. Either wayd. None of the above

Holes act likea. Atomsb. Crystalsc. Negative chargesd. Positive charges

Trivatent atoms have how many valence electrons?a. 1b. 3c. 4d. 5

A donor atom has how many valence electrons?a. 1b. 3c. 4d. 5

If you wanted to produce a p-type semiconductor, which of these would you use?a. Acceptor atomsb. Donor atomsc. Pentavalent impurityd. Silicon

Holes are the minority carriers in which type of semiconductor?a. Extrinsicb. Intrinsicc. n-typed. p-type

How many free electrons does a p-type semiconductor contain?a. Manyb. Nonec. Only those produced by thermal energyd. Same number as holesSilver is the best conductor. How many valence electrons do you think it has?a. 1b. 4c. 18d. 29

Suppose an intrinsic semiconductor has 1 billion free electrons at room temperature. If the temperature changes to 75'C, how many holes are there?a. Fewer than 1 billionb. 1 billionc. More than 1 billiond. Impossible to say

An external voltage source is applied to a p-type semiconductor. If the left end of the crystal is positive, which way do the majority carriers flow?a. Leftb. Rightc. Neitherd. Impossible to say

Which of the following doesn't fit in the group?a. Conductorb. Semiconductorc. Four valence electronsd. Crystal structure

Which of the following is approximately equal to room temperature?a. 0 degrees Cb. 25 degrees Cc. 50 degrees Cd. 75degrees C

How many electrons are there in the valence orbit of a silicon atom within a crystal?a. 1b. 4c. 8d. 14

Positive ions are atoms that havea. Gained a protonb. Lost a protonc. Gained an electrond. Lost an electron

Which of the following describes an n-type semiconductor?a. Neutralb. Positively chargedc. Negatively chargedd. Has many holes

A p-type semiconductor contains holes anda. Positive ionsb. Negative ionsc. Pentavalent atomsd. Donor atoms

Which of the following describes a p-type semiconductor?a. Neutralb. Positively chargedc. Negatively chargedd. Has many free electrons

Which of the following cannot move?a. Holesb. Free electronsc. Ionsd. Majority carriers

What causes the depletion layer?a. Dopingb. Recombinationc. Barrier potentiald. Ions

What is the barrier potential of a silicon diode at room temperature?a. 0.3 Vb. 0.7 Vc. 1 Vd. 2 mV per degree Celsius

To produce a large forward current in a silicon diode, the applied voltage must be greater thana. 0b. 0.3 Vc. 0.7 Vd. 1 V

In a silicon diode the reverse current is usuallya. Very smallb. Very largec. Zerod. In the breakdown region

Surface-leakage current is part of thea. Forward currentb. Forward breakdownc. Reverse currentd. Reverse breakdown

The voltage where avalanche occurs is called thea. Barrier potentialb. Depletion layerc. Knee voltaged. Breakdown voltage

Diffusion of free electrons across the junction of an unbiased diode producesa. Forward biasb. Reverse biasc. Breakdownd. The depletion layer

When the reverse voltage increases from 5 to 10 V, the depletion layera. Becomes smallerb. Becomes largerc. Is unaffectedd. Breaks down

When a diode is forward-biased, the recombination of free electrons and holes may producea. Heatb. Lightc. Radiationd. All of the above

When the graph of current versus voltage is a straight line, the device is referred to as a. Activeb. Linearc. Nonlineard. Passive

What kind of device is a resistor?a. Unilateralb. Linearc. Nonlineard. Bipolar

What kind of a device is a diode?a. Bilateralb. Linearc. Nonlineard. Unipolar

How is a nonconducting diode biased?a. Forwardb. Inversec. Poorlyd. Reverse

When the diode current is large, the bias isa. Forwardb. Inversec. Poord. Reverse

The knee voltage of a diode is approximately equal to thea. Applied voltageb. Barrier potentialc. Breakdown voltaged. Forward voltage

The reverse current consists of minority-carrier current anda. Avalanche currentb. Forward currentc. Surface-leakage currentd. Zener current

How much voltage is there across the second approximation of a silicon diode when it is forward biased?a. 0b. 0.3 Vc. 0.7 Vd. 1 V

How much current is there through the second approximation of a silicon diode when it is reverse biased?a. 0b. 1 mAc. 300 mAd. None of the above

How much forward diode voltage is there with the ideal-diode approximation?a. 0b. 0.7 Vc. More than 0.7 Vd. 1 V

The bulk resistance of a 1N4001 isa. 0b. 0.23 ohm c. 10 ohm d. 1 kohmIf the bulk resistance is zero, the graph above the knee becomesa. Horizontalb. Verticalc. Tilted at 450d. None of the above

The ideal diode is usually adequate when

a. Troubleshootingb. Doing precise calculationsc. The source voltage is lowd. The load resistance is low

The second approximation works well whena. Troubleshootingb. Load resistance is highc. Source voltage is highd. All of the above

The only time you have to use the third approximation is whena. Load resistance is lowb. Source voltage is highc. Troubleshootingd. None of the above

How much load current is there in Fig. 3-19 (see your textbook) with the ideal diode?a. 0b. 14.3 mAc. 15 mAd. 50 mA

How much load current is there in Fig. 3-19 (see your textbook) with the second approximation?a. 0b. 14.3 mAc. 15 mAd. 50 mA

How much load current is there in Fig. 3-19 with the third approximation?a. 0b. 14.3 mAc. 15 mAd. 50 mA

If the diode is open in Fig. 3-19, the load voltage isa. 0b. 14.3 Vc. 20 Vd. -15 V

If the resistor is ungrounded in Fig. 3-19, the voltage measured with a DMM between the top of the resistor and ground is closest toa. 0b. 15 Vc. 20 Vd. -15 V

The load voltage measures zero in Fig. 3-19. The trouble may bea. A shorted diodeb. An open diodec. An open load resistord. Too much supply voltage

If N1/N2 = 2, and the primary voltage is 120 V, what is the secondary voltage?a. 0 Vb. 36 Vc. 60 V d. 240 V

In a step-down transformer, which is larger?a. Primary voltageb. Secondary voltagec. Neitherd. No answer possible

A transformer has a turns ratio of 4: 1. What is the peak secondary voltage if 115 V rms is applied to the primary winding?a. 40.7 V b. 64.6 V c. 163 V d. 650 V

With a half-wave rectified voltage across the load resistor, load current flows for what part of a cycle?a. 0 degreesb. 90 degreesc. 180 degreesd. 360 degrees

Line voltage may be from 105 V rms to 125 rms in a half-wave rectifier. With a 5:1 step-down transformer, the maximum peak load voltage is closest toa. 21 V b. 25 V c. 29.6 V d. 35.4 V

The voltage out of a bridge rectifier is aa. Half-wave signalb. Full-wave signalc. Bridge-rectified signald. Sine wave

If the line voltage is 115 V rms, a turns ratio of 5: 1 means the rms secondary voltage is closest toa. 15 V b. 23 V c. 30 V d. 35 V

What is the peak load voltage in a full-wave rectifier if the secondary voltage is 20 V rms?a. 0 V b. 0.7 V c. 14.1 V d. 28.3 V

We want a peak load voltage of 40 V out of a bridge rectifier. What is the approximate rms value of secondary voltage?a. 0 V b. 14.4 V c. 28.3 V d. 56.6 V

With a full-wave rectified voltage across the load resistor, load current flows for what part of a cycle?a. 0 degreesb. 90 degreesc. 180 degreesd. 360 degreesWhat is the peak load voltage out of a bridge rectifier for a secondary voltage of 15 V rms? (Use second approximation.)a. 9.2 V b. 15 V c. 19.8 V d. 24.3 V

If line frequency is 60 Hz, the output frequency of a half-wave rectifier isa. 30 Hz b. 60 Hz c. 120 Hz d. 240 Hz

If line frequency is 60 Hz, the output frequency of a bridge rectifier isa. 30 Hz b. 60 Hz c. 120 Hz d. 240 Hz

With the same secondary voltage and filter, which has the most ripple?a. Half-wave rectifierb. Full-wave rectifierc. Bridge rectifierd. Impossible to say

With the same secondary voltage and filter, which produces the least load voltage?a. Half-wave rectifierb. Full-wave rectifier

c. Bridge rectifierd. Impossible to say

If the filtered load current is 10 mA, which of the following has a diode current of 10 mA?a. Half-wave rectifierb. Full-wave rectifierc. Bridge rectifierd. Impossible to say

If the load current is 5 mA and the filter capacitance is 1000uF, what is the peak-to-peak ripple out of a bridge rectifier?a. 21.3 pV b. 56.3 nV c. 21.3 mV d. 41.7 mV

The diodes in a bridge rectifier each have a maximum dc current rating of 2 A. This means the dc load current can have a maximum value ofa. 1 A b. 2 A c. 4 A d. 8 A

What is the PIV across each diode of a bridge rectifier with a secondary voltage of 20 V rms?a. 14.1 V b. 20 V c. 28.3 V d. 34 V

A zener diodea. Is a batteryb. Has a constant voltage in the breakdown regionc. Has a barrier potential of 1 Vd. Is forward-biasedIf the secondary voltage increases in a bridge rectifier with a capacitor-input filter, the load voltage willa. Decreaseb. Stay the samec. Increased. None of these

If the filter capacitance is increased, the ripple willa. Decreaseb. Stay the samec. Increased. None of these

What is true about the breakdown voltage in a zener diode?a. It decreases when current increases.b. It destroys the diode.c. It equals the current times the resistance.d. It is approximately constant.

Which of these is the best description of a zener diode?a. It is a rectifier diode.b. It is a constant-voltage device.c. It is a constant-cuffent device.d. It works in the forward region.

The voltage across the zener resistance is usuallya. Smallb. Largec. Measured in voltsd. Subtracted from the breakdown voltage

If the series resistance decreases in an unloaded zener regulator, the zener currenta. Decreasesb. Stays the samec. Increasesd. Equals the voltage divided by the resistance

In the second approximation, the total voltage across the zener diode is the sum of-the breakdown voltage and the voltage across thea. Sourceb. Series resistor

c. Zener resistanced. Zener diode

The load voltage is approximately constant when a zener diode isa. Forward-biasedb. Reverse-biasedc. Operating in the breakdown regiond. Unbiased

In a loaded zener regulator, which is the largest current?a. Series currentb. Zener currentc. Load currentd. None of these

If the load resistance decreases in a zener regulator, the zener currenta. Decreasesb. Stays the samec. Increasesd. Equals the source voltage divided by the series resistance

If the load resistance decreases in a zener regulator, the series currenta. Decreasesb. Stays the samec. Increasesd. Equals the source voltage divided by the series resistance

When the source voltage increases in a zener regulator, which of these currents remains approximately constant?a. Series currentb. Zener currentc. Load currentd. Total current

If the zener diode in a zener regulator is connected with the wrong polarity, the load voltage will be closest toa. 0.7 V b. 10 V c. 14 V d. 18 V

At high frequencies, ordinary diodes don't work properly because ofa. Forward biasb. Reverse biasc. Breakdownd. Charge storage

The capacitance of a varactor diode increases when the reverse voltage across ita. Decreasesb. Increasesc. Breaks downd. Stores charges

Breakdown does not destroy a zener diode provided the zener current is less than thea. Breakdown voltageb. Zener test currentc. Maximum zener current ratingd. Banier potential

To display the digit 8 in a seven-segment indicator,a. C must be lightedb. G must be offc. F must be ond. All segments must be on

A photodiode is normallya. Forward-biasedb. Reverse-biasedc. Neither forward- nor reverse-biasedd. Emitting light

When the light increases, the reverse minority carrier current in a photodiode

a. Decreasesb. Increasesc. Is unaffectedd. Reverses direction

The device associated with voltage-controlled capacitance is aa. Light-emitting diodeb. Photodiodec. Varactor dioded. Zener diode

If the depletion layer gets wider, the capacitancea. Decreasesb. Stays the samec. Increasesd. Is variable

When the reverse voltage increases, the capacitancea. Decreasesb. Stays the samec. Increasesd. Has more bandwidth

The varactor is usuallya. Forward-biasedb. Reverse-biasedc. Unbiasedd. Operated in the breakdown region

The device to use for rectifying a weak ac signal is aa. Zener diodeb. Light-emitting diodec. Varistord. Back diode

Which of the following has a negative-resistance region?a. Tunnel diodeb. Step-recovery diodec. Schottky dioded. Optocoupler

A blown-fuse indicator uses aa. Zener diodeb. Constant-cuffent diodec. Light-emitting dioded. Back diode

To isolate an output circuit from an input circuit, which is the device to use?a. Back diodeb. Optocouplerc. Seven-segment indicatord. Tunnel diode

The diode with a forward voltage drop of approximately 0.25 V is thea. Step-recovery diodeb. Schottky diodec. Back dioded. Constant-current diode

For typical operation, you need to use reverse bias with aa. Zener diodeb. Photodiodec. Varactord. All of the above

A transistor has how many doped regions?a. 1b. 2 c. 3 d. 4

What is one important thing transistors do?a. Amplify weak signalsb. Rectify line voltageC. Regulate voltage

d. Emit light

Who invented the first junction transistor?a. Bellb. Faradayc. Marconid. Schockley

In an npn transistor, the majority carriers in the base area. Free electronsb. Holesc. Neitherd. Both

The barrier potential across each silicon depletion layer isa. 0 b. 0.3 Vc. 0.7 V d. 1 V

The emitter diode is usuallya. Forward-biasedb. Reverse-biasedc. Nonconductingd. Operating in the breakdown region

For normal operation of the transistor, the collector diode has to bea. Forward-biasedb. Reverse-biasedc. Nonconductingd. Operating in the breakdown region

The base of an npn transistor is thin anda. Heavily dopedb. Lightly dopedc. Metallicd. Doped by a pentavalent material

Most of the electrons in the base of an npn transistor flowa. Out of the base leadb. Into the collectorc. Into the emitterd. Into the base supply

Most of the electrons in the base of an npn transistor do not recombine because theya. Have a long lifetimeb. Have a negative chargec. Must flow a long way through the based. Flow out of the base

Most of the electrons that flow through the base willa. Flow into the collectorb. Flow out of the base leadc. Recombine with base holesd. Recombine with collector holes

The current gain of a transistor is the ratio of thea. Collector current to emitter currentb. Collector current to base currentc. Base current to collector currentd. Emitter current to collector current

Increasing the collector supply voltage will increasea. Base currentb. Collector currentc. Emitter currentd. None of the above

The fact that only a few holes are in the base region means the base isa. Lightly dopedb. Heavily dopedc. Undopedd. None of the above

In a normally biased npn transistor, the electrons in the emitter have enough energy to overcome the barrier potential of the

a. Base-emitter junctionb. Base-collector junctionc. Collector-base junctiond. Recombination path

When a free electron recombines with a hole in the base region, the free electron becomes a. Another free electronb. A valence electronc. A conduction-band electrond. A majority carrier

What is the most important fact about the collector current?a. It is measured in milliamperes.b. It equals the base current divided by the current gain.c. It is small.d. It approximately equals the emitter current.

If the current gain is 200 and the collector current is 100 mA, the base current isa. 0.5 mA b. 2 mAc. 2 A d. 20 A

The base-emitter voltage is usuallya. Less than the base supply voltageb. Equal to the base supply voltagec. More than the base supply voltaged. Cannot answer

The collector-emitter voltage is usuallya. Less than the collector supply voltageb. Equal to the collector supply voltagec. More than the collector supply voltaged. Cannot answer

The power dissipated by a transistor approximately equals the collector current timesa. Base-emitter voltageb. Collector-emitter voltagec. Base supply voltaged. 0.7 V

A small collector current with zero base current is caused by the leakage current of thea. Emitter diodeb. Collector diodec. Base dioded. Transistor

A transistor acts like a diode and aa. Voltage sourceb. Current sourcec. Resistanced. Power supply

If the base current is 100 mA and the current gain is 30, the collector current isa. 300 mA b. 3 Ac. 3.33 A d. 10 A

The base-emitter voltage of an ideal transistor isa. 0 b. 0.3 Vc. 0.7 V d. 1 V

If you recalculate the collector-emitter voltage with the second approximation, the answer will usually bea. Smaller than the ideal valueb.. The same as the ideal valuec. Larger than the ideal valued. Inaccurate

In the active region, the collector current is not changed significantly bya. Base supply voltageb. Base currentc. Current gaind. Collector resistance

The base-emitter voltage of the second approximation isa. 0 b. 0.3 Vc. 0.7 V d. 1 V

If the base resistor is open, what is the collector cuffent?a. 0 b. 1 mAc. 2 mA d. 10 mA

The current gain of a transistor is defined as the ratio of the collector current to thea. Base currentb. Emitter currentc. Supply currentd. Collector current

The graph of current gain versus collector-current indicates that the current gaina. Is constantb. Varies slightlyc. Varies significantlyd. Equals the collector current divided by the base current

When the collector current increases, what does the current gain do?a. Decreasesb. Stays the samec. Increasesd. Any of the above

As the temperature increases, the current gaina. Decreasesb. Remains the samec. Increasesd. Can be any of the above

When the base resistor decreases, the collector voltage will probablya. Decreaseb. Stay the samec. Increased. Do all of the above

If the base resistor is very small, the transistor will operate in thea. Cutoff regionb. Active regionc. Saturation regiond. Breakdown region

Ignoring the bulk resistance of the collector diode, the collector-emitter saturation voltage isa. 0b. A few tenths of a voltC. 1 Vd. Supply voltage

Three different Q points are shown on a load line. The upper Q point represents thea. Minimum current gainb. Intermediate current gainc. Maximum current gaind. Cutoff point

If a transistor operates at the middle of the load line, an increase in the base resistance will move the Q pointa. Downb. Upc. Nowhere

d. Off the load line

If a transistor operates at the middle of the load line, an increase in the current gain will move the Q pointa. Downb. Upc, Nowhered. Off the load line

If the base supply voltage increases, the Q point movesa. Downb. Upc. Nowhered. Off the load line

Suppose the base resistor is open. The Q point will bea. In the middle of the load lineb. At the upper end of the load linec. At the lower end of the load lined. Off the load line

If the base supply voltage is disconnected, the collector-emitter voltage will equala. 0 Vb. 6 Vc. 10.5 Vd. Collector supply voltage

If the base resistor is shorted, the transistor will probably bea. Saturatedb. In cutoffc. Destrovedd. None of the above

If the collector resistor decreases to zero in a base-biased circuit, the load line will becomea. Horizontal b. Verticalc. Useless d. Flat

The collector current is 10 mA. If the current gain is 100, the base current isa. 1 microamp b. 10 microamp c. 100 microamp d. 1 mA

The base current is 50 microamp. If the current gain is 125, the collector current is closest in value toa. 40 microampb. 500 microampc. 1 mA d. 6 mA

When the Q point moves along the load line, the voltage increases when the collector currenta. Decreasesb. Stays the samec. Increasesd. Does none of the above

When there is no base current in a transistor switch, the output voltage from the transistor isa. Lowb. Highc. Unchangedd. Unknown

A circuit with a fixed emitter current is calleda. Base biasb. Emitter biasc. Transistor biasd. Two-supply bias

The first step in analyzing emitter-based circuits is to find the

a. Base currentb. Emitter voltagec. Emitter currentd. Collector current

If the current gain is unknown in an emitter-biased circuit, you cannot calculate thea. Emitter voltageb. Emitter currentc. Collector currentd. Base current

If the emitter resistor is open, the collector voltage isa. Low b. High c. Unchanged d. Unkiiown

If the collector resistor is open, the collector voltage isa. Low b. Highc. Unchanged d. Unknown

When the current gain increases from 50 to 300 in an emitter-biased circuit, the collector currenta. Remains almost the sameb. Decreases by a factor of 6c. Increases by a factor of 6d. Is zero

If the emitter resistance decreases, the collector voltagea. Decreasesb. Stays the samec. Increasesd. Breaks down the transistor

If the emitter resistance decreases, thea. Q point moves upb. Collector current decreasesc. Q point stays where it isd. Current gain increases

For emitter bias, the voltage across the emitter resistor is the same as the voltage between the emitter and thea. Baseb. Collectorc. Emitterd. Ground

For emitter bias, the voltage at the emitter is 0.7 V less than thea. Base voltageb. Emitter voltagec. Collector voltaged. Ground voltage

With voltage-divider bias, the base voltage isa. Less than the base supply voltageb. Equal to the base supply voltagec. Greater than the base supply voltaged. Greater than the collector supply voltage

VDB is noted for itsa. Unstable collector voltageb. Varying emitter currentc. Large base currentd. Stable Q point

With VDB, an increase in emitter resistance willa. Decrease the emitter voltageb. Decrease the collector voltagec. Increase the emitter voltaged. Decrease the emitter current

VDB has a stable Q point likea. Base bias

b. Emitter biasc. Collector-feedback biasd. Emitter-feedback bias

VDB needsa. Only three resistorsb. Only one supplyc. Precision resistorsd. More resistors to work better

VDB normally operates in thea. Active regionb. Cutoff regionc. Saturation regiond. Breakdown region

The collector voltage of a VDB circuit is not sensitive to changes in thea. Supply voltageb. Emitter resistancec. Current gaind. Collector resistance

If the emitter resistance increases in a VDB circuit, the collector voltagea. Decreasesb. Stays the samec. Increasesd. Doubles

Base bias is associated witha. Amplifiersb. Switching circuitsc. Stable Q pointd. Fixed emitter current

If the emitter resistance doubles in a VDB circuit, the collector current willa. Doubleb. Drop in halfc. Remain the samed. Increase

If the collector resistance increases in a VDB circuit, the collector voltage willa. Decreaseb. Stay the samec. Increased. Double

The Q point of a VDB circuit isa. Hypersensitive to changes in current gainb. Somewhat sensitive to changes in current gainc. Almost totally insensitive to changes in current gaind. Greatly affected by temperature changes

The base voltage of two-supply emitter bias (TSEB) isa. 0.7 Vb. Very largec. Near 0 Vd. 1.3 V

If the emitter resistance doubles with TSEB, the collector current willa. Drop in halfb. Stay the samec. Doubled. Increase

If a splash of solder shorts the collector resistor of TSEB, the collector voltage willa. Drop to zerob. Equal the collector supply voltagec. Stay the samed. Double

If the emitter resistance increases with TSEB, the collector voltage willa. Decreaseb. Stay the samec. Increased. Equal the collector supply voltage

If the emitter resistor opens with TSEB, the collector voltage willa. Decreaseb. Stay the samec. Increase slightlyd. Equal the collector supply voltage

In TSEB, the base current must be verya. Smallb. Largec. Unstabled. Stable

The Q point of TSEB does not depend on thea. Emitter resistanceb. Collector resistancec. Current gaind. Emitter voltage

The majority carriers in the emitter of a pnp transistor area. Holes b. Free electronsc. Trivalent atoms d. Pentavalent atoms

The current gain of a pnp transistor isa. The negative of the npn current gainb. The collector current divided by the emitter currentc. Near zerod. The ratio of collector current to base current

Which is the largest current in a pnp transistor?a. Base currentb. Emitter currentc. Collector currentd. None of these

The currents of a pnp transistor area. Usually smaller than npn currentsb. Opposite npn currentsc. Usually larger than npn currentsd. Negative

With pnp voltage-divider bias, you must usea. Negative power suppliesb. Positive power suppliesc. Resistorsd. Grounds

For dc, the current in a coupling circuit is a. Zero b. Maximum c. Minimum d. Average

The current in a coupling circuit for high frequencies is a. Zero b. Maximum c. Minimum d. Average

A coupling capacitor is a. A dc shortb. An ac openc. A dc open and an ac shortd. A dc short and an ac open

In a bypass circuit, the top of a capacitor isa. An openb. A shortc. An ac groundd. A mechanical ground

The capacitor that produces an ac ground is called a

a. Bypass capacitorb. Coupling capacitorc. Dc opend. Ac open

The capacitors of a CE amplifier appear a. Open to ac b. Shorted to dc c. Open to supply voltage d. Shorted to ac

Reducing all dc sources to zero is one of the steps in getting thea. DC equivalent circuitb. AC equivalent circuitc. Complete amplifier circuitd. Voltage-divider biased circuit

The ac equivalent circuit is derived from the original circuit by shorting alla. Resistorsb. Capacitorsc. Inductorsd. Transistors

When the ac base voltage is too large, the ac emitter current isa. Sinusoidalb. Constantc. Distortedd. Alternating

In a CE amplifier with a large input signal, the positive half cycle of the ac emitter current isa. Equal to the negative half cycleb. Smaller than the negative half cyclec. Larger than the negative half cycled. Equal to the negative half cycle

Ac emitter resistance equals 25 mV divided by thea. Quiescent base currentb. DC emitter currentc. AC emitter currentd. Change in collector current

To reduce the distortion in a CE amplifier, reduce thea. DC emitter currentb. Base-emitter voltagec. Collector currentd. AC base voltage

If the ac voltage across the emitter diode is 1 mV and the ac emitter current is 0.1 mA, the ac resistance of the emitter diode is a. 1 ohm b. 10 ohm c. 100 ohm d. 1 kohm

A graph of ac emitter current versus ac base-emitter voltage applies to thea. Transistorb. Emitter diodec. Collector dioded. Power supplyThe output voltage of a CE amplifier isa. Amplifiedb. Invertedc. 180 degrees out of phase with the inputd. All of the above

The emitter of a CE amplifier has no ac voltage because of thea. DC voltage on itb. Bypass capacitorc. Coupling capacitord. Load resistor

The voltage across the load resistor of a CE amplifier isa. Dc and ac b. DC only c. AC onlyd. Neither dc nor ac

The ac collector current is approximately equal to thea. AC base currentb. AC emitter currentc. AC source currentd. AC bypass current

The ac emitter current times the ac emitter resistance equals thea. Dc emitter voltageb. AC base voltagec. AC collector voltaged. Supply voltage

The ac collector current equals the ac base current times thea. AC collector resistanceb. DC current gainc. AC current gaind. Generator voltage

The emitter is at ac ground in aa. CB stageb. CC stagec. CE staged. None of these

The output voltage of a CE stage is usuallya. Constantb. Dependent on re'c. Smalld. Less the one

The voltage gain equals the output voltage divided by thea. Input voltageb. AC emitter resistancec. AC collector resistanced. Generator voltage

The input impedance of the base increases whena. Beta increasesb. Supply voltage increasesc. Beta decreasesd. AC collector resistance increases

Voltage gain is directly proportional toa. Betab. Ac emitter resistancec. DC collector voltaged. AC collector resistance

Compared to the ac resistance of the emitter diode, the feedback resistance of a swamped amplifier should bea. Small b. Equalc. Large d. Zero

Compared to a CE stage, a swamped amplifier has an input impedance that isa. Smaller b. Equalc. Largerd. Zero

To reduce the distortion of an amplified signal, you can increase thea. Collector resistanceb. Emitter feedback resistancec. Generator resistanced. Load resistance

The emitter of a swamped amplifiera. Is groundedb. Has no de voltagec. Has an ac voltaged. Has no ac voltage

A swamped amplifier uses

a. Base biasb. Positive feedbackc. Negative feedbackd. A grounded emitter

In a swamped amplifier, the effects of the emitter diode becomea. Important to voltage gainb. Critical to input impedancec. Significant to the analysisd. Unimportant

The feedback resistora. Increases voltage gainb. Reduces distortionc. Decreases collector resistanced. Decreases input impedance

The feedback resistora. Stabilizes voltage gainb. Increases distortionc. Increases collector resistanced. Decreases input impedance

The ac collector resistance of the first stage includes thea. Load resistanceb. Input impedance of first stagec. Emitter resistance of first staged. Input impedance of second stage

If the emitter bypass capacitor opens, the ac output voltage willa. Decrease b. Increasec. Remain the same d. Equal zero

If the collector resistor is shorted, the ac output voltage willa. Decrease b. Increasec. Remain the same d. Equal zero

If the load resistance is open, the ac output voltage willa. Decrease b. Increasec. Remain the same d. Equal zero

If any capacitor is open, the ac output voltage willa. Decrease b. Increasec. Remain the same d. Equal zero

If the input coupling capacitor is open, the ac input voltage willa. Decrease b. Increasec. Remain the samed. Equal zero

If the bypass capacitor is open, the ac input voltage willa. Decreaseb. Increasec. Remainthe samed. Equal zero

If the output coupling capacitor is open, the ac input voltage willa. Decrease b. Increasec. Remain the samed. Equal zero

If the emitter resistor is open, the ac input voltage willa. Decrease b. Increasec. Remain the same d. Equal zero

If the collector resistor is open, the ac input voltage will

a. Decreaseb. Increasec. Remain the samed. Equal approximately zero

If the emitter bypass capacitor is shorted, the ac input voltage willa. Decrease b. Increase c. Remain the same d. Equal zero

For class B operation, the collector current flowsa. The whole cycleb. Half the cyclec. Less than half a cycled. Less than a quarter of a cycle

Transformer coupling is an example ofa. Direct couplingb. AC couplingc. DC couplingd. Impedance coupling

An audio amplifier operates in the frequency range ofa. 0 to 20 Hzb. 20 Hz to 20 kHzc. 20 to 200 kHzd. Above 20 kHz

A tuned RF amplifier isa. Narrowbandb. Widebandc. Direct coupledd. Impedance coupled

The first stage of a preamp isa. A tuned RF stageb. Large signalc. Small signald. A dc amplifier

For maximum peak-to-peak output voltage, the Q point should bea. Near saturationb. Near cutoffc. At the center of the dc load lined. At the center of the ac load line

An amplifier has two load lines becausea. It has ac and dc collector resistancesb. It has two equivalent circuitsc. DC acts one way and ac acts anotherd. All of the above

When the Q point is at the center of the ac load line, the maximum peak-to-peak output voltage equalsa. VCEQb. 2VCEQc. ICQd. 2IcQ

Push-pull is almost always used witha. Class A b. Class B c. Class Cd. All of the above

One advantage of a class B push-pull amplifier isa. Very small quiescent current drainb. Maximum efficiency of 78.5 percentc. Greater efficiency than class Ad. All of the above

Class C amplifiers are almost alwaysa. Transformer-coupled between stagesb. Operated at audio frequencies

c. Tuned RF amplifiersd. Wideband

The input signal of a class C amplifiera. Is negatively clamped at the baseb. Is amplified and invertedc. Produces brief pulses of collector currentd. All of the above

The collector current of a class C amplifiera. Is an amplified version of the input voltageb. Has harmonicsc. Is negatively clampedd. Flows for half a cycle

The bandwidth of a class C amplifier decreases when thea. Resonant frequency increasesb. Q increasesc. XL decreasesd. Load resistance decreases

The transistor dissipation in a class C amplifier decreases when thea. Resonant frequency increasesb. coil Q increasesc. Load resistance decreasesd. Capacitance increases

The power rating of a transistor can be increased bya. Raising the temperatureb. Using a heat sinkc. Using a derating curved. Operating with no input signal

The ac load line is the same as the dc load line when the ac collector resistance equals thea. DC emitter resistanceb. AC emitter resistancec. DC collector resistanced. Supply voltage divided by collector current

If RC = 3.6 kohm and RL = 10 kohm, the ac load resistance equalsa. 10 kohm b. 2.65 kohmc. I kohm d. 3.6 kohm

The quiescent collector current is the same as thea. DC collector currentb. AC collector currentc. Total collector currentd. Voltage-divider current

The ac load line usuallya. Equals the dc load lineb. Has less slope than the dc load linec. Is steeper than the dc load lined. Is horizontal

For a Q point near the center of the dc load line, clipping is more likely to occur on thea. Positive peak of input voltageb. Negative peak of output voltagec. Positive peak of output voltaged. Negative peak of emitter voltage

In a class A amplifier, the collector current flows fora. Less than half the cycleb. Half the cyclec. Less than the whole cycled. The entire cycle

With class A, the output signal should bea. Unclippedb. Clipped on positive voltage peakc. Clipped on negative voltage peakd. Clipped on negative current peak

The instantaneous operating point swings-along thea. AC load lineb. DC load linec. Both load linesd. Neither load line

The current drain of an amplifier is thea. Total ac current from the generatorb. Total dc current from the supplyc. Current gain from base to collectord. Current gain from collector to baseThe power gain of an amplifiera. Is the same as the voltage gainb. Is smaller than the voltage gainc. Equals output power divided by input powerd. Equals load power

Heat sinks reduce thea. Transistor powerb. Ambient temperaturec. Junction temperatured. Collector current

When the ambient temperature increases, the maximum transistor power ratinga. Decreasesb. Increasesc. Remains the samed. None of the above

If the load power is 3 mW and the dc power is 150 mW, the efficiency isa. 0 b. 2 percentc. 3 percent d. 20 percent

An emitter follower has a voltage gain that isa. Much less than oneb. Approximately equal to onec. Greater than oned. Zero

The total ac emitter resistance of an emitter follower equalsa. re'b. rec. re + re'd. RE

The input impedance of the base of an emitter follower is usuallya. Lowb. Highc. Shorted to groundd. Open

The dc emitter current for class A emitter followers isa. The same as the ac emitter currentb. VE divided by REc. Vc divided by Rcd. The same as the load current

The ac base voltage of an emitter follower is across thea. Emitter diodeb. DC emitter resistorc. Load resistord. Emitter diode and external ac emitter resistance

The output voltage of an emitter follower is across thea. Emitter diodeb. DC collector resistorc. Load resistord. Emitter diode and external ac emitter resistance

If Beta = 200 and re = 150 ohm, the input impedance of the base is approximatelya. 30 kohmb. 600 nc. 3 kohmd. 5 kohm

The input voltage to an emitter follower is usuallya. Less than the generator voltageb. Equal to the generator voltagec. Greater than the generator voltaged. Equal to the supply voltage

The ac emitter current is closest toa. VG divided by reb. vin divided by re'c. VG divided by re'd. vin divided by re

The output voltage of an emitter follower is approximatelya. 0 b. VGc. vin d. Vcc

The ac load line of an emitter follower is usuallya. The same as the dc load lineb. More horizontal than the dc load linec. Steeper than the dc load lined. Vertical

If the input voltage to an emitter follower is too large, the output voltage will bea. Smallerb. Largerc. Equald. Clipped

If the Q point is at the middle of the dc load line, clipping will first occur on thea. Left voltage swingb. Upward current swingc. Positive half cycle of inputd. Negative half cycle of input

If an emitter follower has VCEQ = 5 V, ICQ = 1 mA, and re = 1 kohm, the maximum peak-to-peak unclipped output isa. 1 V b. 2 V c. 5 V d. 10 V

If the load resistance of an emitter follower is very large, the external ac emitter resistance equalsa. Generator resistanceb. Impedance of the basec. DC emitter resistanced. DC collector resistance

If an emitter follower has re' = 10 ohm and re = 90 ohm, the voltage gain is approximatelya. 0b. 0.5c. 0.9d. 1

A square wave out of an emitter follower impliesa. No clippingb. Clipping at saturationc. Clipping at cutoffd. Clipping on both peaks

A Darlington transistor hasa. A very low input impedanceb. Three transistorsc. A very high current gaind. One VBE drop

The ac load line of the emitter follower isa. The same as the dc load line

b. Different from the dc load linec. Horizontald. Vertical

If the generator voltage is 5 mV in an emitter follower, the output voltage across the load is closest toa. 5 mVb. 150 mVc. 0.25 Vd. 0.5 V

If the load resistor of Fig. 12-la in your textbook is shorted, which of the following are different from their normal values:a. Only ac voltagesb. Only dc voltagesc. Both dc and ac voltagesd. Neither dc nor ac voltages

If R1 is open in an emitter follower, which of these is true?a. DC base voltage is Vccb. DC collector voltage is zeroc. Output voltage is normald. DC base voltage is zero

Usually, the distortion in an emitter follower isa. Very lowb. Very highc. Larged. Not acceptable

The distortion in an emitter follower isa. Seldom lowb. Often highc. Always lowd. High when clipping occurs

If a CE stage is direct coupled to an emitter follower, how many coupling capacitors are there between the two stages?a. 0b. 1c. 2d. 3

A Darlington transistor has a Beta of 8000. If RE = 1 kohm and RL = 100 ohm, the input impedance of the base is closest toa. 8 kohm b. 80 kohm c. 800 kohm d. 8 Mohm

The transistors of a class B push-pull emitter follower are biased at or neara. Cutoffb. The center of the dc load linec. Saturationd. The center of the ac load line

Thermal runaway isa. Good for transistorsb. Always desirablec. Useful at timesd. Usually destructive

The ac resistance of compensating diodesa. Must be includedb. Is usually small enough to ignorec. Compensates for temperature changesd. Is very high

A small quiescent current is necessary with a class B push-pull amplifier to avoida. Thermal runawayb. Destroying the compensating diodesc. Crossover distortion

d. Excessive current drain

The zener current in a zener follower isa. Equal to the output currentb. Smaller than the output currentc. Larger than the output currentd. Prone to thermal runaway

In the two-transistor voltage regulator, the output voltagea. Is regulatedb. Has much smaller ripple than the input voltagec. Is larger than the zener voltaged. All of the above

For a class B push-pull emitter follower to work properly, the emitter diodes musta. Be able to control the quiescent currentb. Have a power rating greater than the output powerc. Have a voltage gain of Id. Match the compensating diodes

The maximum efficiency of a class B push-pull amplifier isa. 25 percentb. 50 percentc. 78.5 percentd. 100 percent

The ac emitter resistance of an emitter followera. Equals the dc emitter resistanceb. Is larger than the load resistancec. Has no effect on MPPd. Is usually less than the load resistance

A JFETa. Is a voltage-controlled deviceb. Is a current-controlled devicec. Has a low input resistanced. Has a very large voltage gain

A unipolar transistor usesa. Both free electrons and holesb. Only free electronsc. Only holesd. Either one or the other, but not both

The input impedance of a JFETa. Approaches zerob. Approaches onec. Approaches infinityd. Is impossible to predict

The gate controlsa. The width of the channelb. The drain currentc. The proportional pinchoff voltaged. All the above

The gate-source diode of a JFET should bea. Forward-biasedb. Reverse-biasedc. Either forward- or reverse-biasedd. None of the above

Compared to a bipolar transistor, the JFET has a much highera. Voltage gainb. Input resistancec. Supply voltaged. Current

The pinchoff voltage has the same magnitude as thea. Gate voltageb. Drain-source voltagec. Gate-source voltaged. Gate-source cutoff voltage

When the drain saturation current is less than IDSS, a JFET acts like aa. Bipolar transistor

b. Current sourcec. Resistord. Battery

RDS equals pinchoff voltage divided by thea. Drain currentb. Gate currentc. Ideal drain currentd. Drain current for zero gate voltage

The transconductance curve isa. Linearb. Similar to the graph of a resistorc. Nonlineard. Like a single drain curve

The transconductance increases when the drain current approaches a. 0 b. ID(sat) c. IDSS d. IS

A CS amplifier has a voltage gain of a. gmrd b. gmrs c. gmrs/(l + gmrs) d. gmrd/(l + gmrd)

A source follower has a voltage gain of a. gmrd b. gmrs c. gmrs/(l + gmrs) d. gmrd/(l + gmrd)

When the input signal is large, a source follower hasa. A voltage gain of less than oneb. A small distortionc. A high input resistanced. All of these

The input signal used with a JFET analog switch should be a. Small b. Large c. A square wave d. Chopped

A cascade amplifier has the advantage ofa. Large voltage gainb. Low input capacitancec. Low input impedanced. Higher gm

VHF stands for frequencies froma. 300 kHz to 3 MHzb. 3 to 30 MHzc. 30 to 300 MHzd. 300 MHz to 3 GHz

When a JFET is cut off, the depletion layers are a. Far apart b. Close together c. Touching d. Conducting

When the gate voltage becomes more negative in an n-channel JFET, the channel between the depletion layers a. Shrinks b. Expand c. Conduct d. Stop conducting

If a JFET has IDSS = 10 mA and VP = 2 V, then RDS equalsa. 200 ohm b. 400 ohm c. 1 kohm d. 5 kohm

The easiest way to bias a JFET in the ohmic region is with a. Voltage-divider bias b. Self-bias c. Gate bias d. Source bias

Self-bias produces a. Positive feedback b. Negative feedback c. Forward feedback d. Reverse feedback

To get a negative gate-source voltage in a self-biased JFET circuit, you must have a a. Voltage divider b. Source resistor c. Ground d. Negative gate supply voltage

Transconductance is measured in a. Ohms b. Amperes c. Volts d. Mhos or Siemens

Transconductance indicates how effectively the input voltage controls the a. Voltage gain b. Input resistance c. Supply voltage d. Output current

Which of the following devices revolutionized the computer industry?a. JFETb. D-MOSFETc. E-MOSFETd. Power FET

The voltage that turns on an EMOS device is thea. Gate-source cutoff voltageb. Pinchoff voltagec. Threshold voltaged. Knee voltage

Which of these may appear on the data sheet of an enhancement-mode MOSFET?a. VGS(th)b. ID(on)c. VGS(on)d. All of the above

The VGS(on) of an n-channel E-MOSFET isa. Less than the threshold voltageb. Equal to the gate-source cutoff voltagec. Greater than VDS(on)d. Greater than VGS(th)

An ordinary resistor is an example ofa. A three-terminal deviceb. An active loadc. A passive loadd. A switching device

An E-MOSFET with its gate connected to its drain is an example ofa. A three-terminal deviceb. An active loadc. A passive loadd. A switching device

An E-MOSFET that operates at cutoff or in the ohmic region is an example ofa. A current sourceb. An active loadc. A passive loadd. A switching device

CMOS stands fora. Common MOSb. Active-load switching

c. p-channel and n-channel devicesd. Complementary MOS

VGS(on) is alwaysa. Less than VGS(th)b. Equal to VDS(on)c. Greater than VGS(th)d. Negative

With active-load switching, the upper E-MOSFET is aa. Two-terminal deviceb. Three-terminal devicec. Switchd. Small resistance

CMOS devices use a. Bipolar transistorsb. Complementary E-MOSFETsc. Class A operationd. DMOS devicesThe main advantage of CMOS is itsa. High power ratingb. Small-signal operationc. Switching capabilityd. Low power consumption

Power FETs area. Integrated circuitsb. Small-signal devicesc. Used mostly with analog signalsd. Used to switch large currents

When the internal temperature increases in a power FET, thea. Threshold voltage increasesb. Gate current decreasesc. Drain current decreasesd. Saturation current increases

Most small-signal E-MOSFETs are found ina. Heavy-current applicationsb. Discrete circuitsc. Disk drivesd. Integrated circuits

Most power FETS area. Used in high-current applications b. Digital computersc. RF stagesd. Integrated circuits

An n-channel E-MOSFET conducts when it hasa. VGS > VPb. An n-type inversion layerc. VDS > 0d. Depletion layers

With CMOS, the upper MOSFET isa. A passive loadb. An active loadc. Nonconductingd. Complementary

The high output of a CMOS inverter isa. VDD/2b. VGSc. VDSd. VDD

The RDS(on) of a power FETa. Is always largeb. Has a negative temperature coefficientc. Has a positive temperature coefficientd. Is an active load

A thyristor can be used asa. A resistorb. An amplifierc. A switch

d. A power source

Positive feedback means the returning signala. Opposes the original changeb. Aids the original changec. Is equivalent to negative feedbackd. Is amplified

A latch always usesa. Transistorsb. Feedbackc. Currentd. Positive feedback

To turn on a four-layer diode, you needa. A positive triggerb. low-current drop outc. Breakoverd. Reverse-bias triggering

The minimum input current that can turn on a thyristor is called thea. Holding currentb. Trigger currentc. Breakover currentd. Low-current drop out

The only way to stop a four-layer diode that is conducting is bya. A positive triggerb. Low-current drop outc. Breakoverd. Reverse-bias triggering

The minimum anode current that keeps a thyristor turned on is called thea. Holding currentb. Trigger currentc. Breakover currentd. Low-current drop out

A silicon controlled rectifier hasa. Two external leadsb. Three external leadsc. Four external leadsd. Three doped regions

A SCR is usually turned on bya. Breakoverb. A gate triggerc. Breakdownd. Holding current

SCRs area. Low-power devicesb. Four-layer diodesc. High-current devicesd. Bidirectional

The usual way to protect a load from excessive supply voltage is with aa. Crowbarb. Zener diodec. Four-layer dioded. Thyristor

An RC snubber protects an SCR againsta. Supply overvoltagesb. False triggeringc. Breakoverd. Crowbarring

When a crowbar is used with a power supply, the supply needs to have a fuse ora. Adequate trigger currentb. Holding currentc. Filteringd. Current limitingThe photo-SCR responds to

a. Current b. Voltage c. Humidityd. Light

The diac is aa. Transistorb. Unidirectional devicec. Three-layer deviced. Bidirectional device

The triac is equivalent toa. A four-layer diodeb. Two diacs in parallelc. A thyristor with a gate leadd. Two SCRs in parallel

The unijunction transistor acts as aa. Four-layer diode b. Diac c. Triacd. Latch

Any thyristor can be turned on witha. Breakoverb. Forward-bias triggeringc. Low-current dropoutd. Reverse-bias triggering

A Shockley diode is the same as aa. four-layer diode b. SCRc. diacd. triac

The trigger voltage of an SCR is closest toa. 0b. 0.7 Vc. 4 Vd. Breakover voltage

Any thyristor can be turned off witha. Breakoverb. Forward-bias triggeringc. Low-current drop outd. Reverse-bias triggering

Exceeding the critical rate of rise producesa. Excessive power dissipationb. False triggeringc. Low-current drop outd. Reverse-bias triggering

A four-layer diode is sometimes called aa. Unijunction transistorb. Diacc. pnpn dioded. Switch

A latch is based ona. Negative feedbackb. Positive feedbackc. The four-layer dioded. SCR action

Frequency response is a graph of voltage gain versusa. Frequencyb. Power gainc. Input voltaged. Output voltage

At low frequencies, the coupling capacitors produce a decrease ina. Input resistanceb. Voltage gainc. Generator resistance

d. Generator voltage

The stray-wiring capacitance has an effect on thea. Lower cutoff frequencyb. Midband voltage gainc. Upper cutoff frequencyd. Input resistance

At the lower or upper cutoff frequency, the voltage gain isa. 0.35Amidb. 0.5Amidc. 0.707Amidd. 0.995Amid

If the power gain doubles, the decibel power gain increases bya. A factor of 2 b. 3 dBc. 6 dB d. 10 dB

If the voltage gain doubles, the decibel voltage gain increases bya. A factor of 2b. 3 dB c. 6 dB d. 10 dB

If the voltage gain is 10, the decibel voltage gain isa. 6 dB b. 20 dB c. 40 dB d. 60 dB

If the voltage gain is 100, the decibel voltage gain isa. 6 dB b. 20 dB c. 40 dB d. 60 dB

If the voltage gain is 2000, the decibel voltage gain isa. 40 dBb. 46 dBc. 66 dBd. 86 dB

Two stages have decibel voltage gains of 20 and 40 dB. The total ordinary voltage gain isa.1b. 10 c. 100 d. 1000

Two stages have voltage gains of 100 and 200. The total decibel voltage gain isa. 46 dB b. 66 dB c. 86 dB d. 106 dBOne frequency is 8 times another frequency. How many octaves apart are the two frequencies? a. 1b. 2c. 3d. 4

If f = 1 MHz, and f2 = 10 Hz, the ratio f/f2 represents how many decades?a. 2b. 3c. 4d. 5

Semilogarithmic paper meansa. One axis is linear, and the other is logarithmicb. One axis is linear, and the other is semilogarithmicc. Both axes are semilogarithmicd. Neither axis is linear

If you want to improve the high-frequency response of an amplifier, which of these would you try?

a. Decrease the coupling capacitances.b. Increase the emitter bypass capacitance.c. Shorten leads as much as possible.d. Increase the generator resistance.

The voltage gain of an amplifier decreases 20 dB per decade above 20 kHz. If the midband voltage gain is 86 dB, what is the ordinary voltage gain at 20 MHz?a. 20 b. 200 c. 2000 d. 20,000 Monolithic ICs area. Forms of discrete circuitsb. On a single chipc. Combinations of thin-film and thick-film circuitsd. Also called hybrid ICs

The op amp can amplifya. AC signals onlyb. DC signals onlyc. Both ac and dc signalsd. Neither ac nor dc signals

Components are soldered together ina. Discrete circuitsb. Integrated circuitsc. SSId. Monolithic ICs

The tail current of a diff amp isa. Half of either collector currentb. Equal to either collector currentc. Two times either collector currentd. Equal to the difference in base currents

The node voltage at the top of the tail resistor is closest toa. Collector supply voltageb. Zeroc. Emitter supply voltaged. Tail current times base resistance

The input offset current equals thea. Difference between two base currentsb. Average of two base currentsc. Collector current divided by current gaind. Difference between two base-emitter voltages

The tail current equals thea. Difference between two emitter currentsb. Sum of two emitter currentsc. Collector current divided by current gaind. Collector voltage divided by collector resistance

The voltage gain of a diff amp with a differential output is equal to RC divided bya. re'b. re'/2c. 2re'd. RE

The input impedance of a diff amp equals re' timesa. 0b. RCc. REd. 2 times Beta

A dc signal has a frequency ofa. 0b. 60 Hzc. 0 to over 1 MHzd. 1 MHz

When the two input terminals of a diff amp are grounded,a. The base currents are equalb. The collector currents are equalc. An output error voltage usually existsd. The ac output voltage is zero

One source of output error voltage isa. Input bias currentb. Difference in collector resistorsc. Tail currentd. Common-mode voltage gain

A common-mode signal is applied toa. The noninverting inputb. The inverting inputc. Both inputsd. Top of the tail resistor

The common-mode voltage gain isa. Smaller than voltage gainb. Equal to voltage gainc. Greater than voltage gaind. None of the above

The input stage of an op amp is usually aa. Diff ampb. Class B push-pull amplifierc. CE amplifierd. Swamped amplifier

The tail of a diff amp acts like aa. Batteryb. Current sourcec. Transistord. Diode

The common-mode voltage gain of a diff amp is equal to RC divided bya. re'b. re'/2c. 2re'd. 2RE

When the two bases are grounded in a diff amp, the voltage across each emitter diode isa. Zerob. 0.7 Vc. The samed. High

The common-mode rejection ratio isa. Very lowb. Often expressed in decibelsc. Equal to the voltage gaind. Equal to the common-mode voltage gain

The typical input stage of an op amp has aa. Single-ended input and single-ended outputb. Single-ended input and differential outputc. Differential input and single-ended outputd. Differential input and differential output

The input offset current is usuallya. Less than the input bias currentb. Equal to zeroc. Less than the input offset voltaged. Unimportant when a base resistor is used

With both bases grounded, the only offset that produces an error is thea. Input offset currentb. Input bias currentc. Input offset voltaged. Beta

What usually controls the open-loop cutoff frequency of an op amp?a. Stray-wiring capacitanceb. Base-emitter capacitancec. Collector-base capacitance

d. Compensating capacitance

A compensating capacitor preventsa. Voltage gainb. Oscillationsc. Input offset currentd. Power bandwidth

At the unity-gain frequency, the open-loop voltage gain isa. 1b. Amidc. Zerod. Very large

The cutoff frequency of an op amp equals the unity-gain frequency divided bya. the cutoff frequencyb. Closed-loop voltage gainc. Unityd. Common-mode voltage gain

If the cutoff frequency is 15 Hz and the midband open-loop voltage gain is 1,000,000, the unity-gain frequency isa. 25 Hzb. 1 MHzc. 1.5 MHzd. 15 MHz

If the unity-gain frequency is 5 MHz and the midband open-loop voltage gain is 200,000, the cutoff frequency isa. 25 Hz b. 1 MHz c. 1.5 MHz d. 15 MHz

The initial slope of a sine wave is directly proportional toa. Slew rateb. Frequencyc. Voltage gaind. Capacitance

When the initial slope of a sine wave is greater than the slew rate,a. Distortion occursb. Linear operation occursc. Voltage gain is maximumd. The op amp works best

The power bandwidth increases whena. Frequency decreasesb. Peak value decreasesc. Initial slope decreasesd. Voltage gain increases

A 741C usesa. Discrete resistorsb. Inductorsc. Active-load resistorsd. A large coupling capacitor

A 741C cannot work withouta. Discrete resistorsb. Passive loadingc. Dc return paths on the two basesd. A small coupling capacitor

The input impedance of a BIFET op amp isa. Lowb. Mediumc. Highd. Extremely high

An LF157A is aa. Diff ampb. Source followerc. Bipolar op amp

d. BIFET op amp

If the two supply voltages are plus and minus 15 V, the MPP value of an op amp is closest toa. 0b. +15Vc. -15 Vd. 30 V

The open-loop cutoff frequency of a 741C is controlled bya. A coupling capacitorb. The output short circuit currentc. The power bandwidthd. A compensating capacitorThe 741C has a unity-gain frequency ofa. 10 Hz b. 20 kHz c. 1 MHz d. 15 MHz

The unity-gain frequency equals the product of closed-loop voltage gain and thea. Compensating capacitanceb. Tail currentc. Closed-loop cutoff frequencyd. Load resistance

If funity is 10 MHz and midband open-loop voltage gain is 1,000,000, then the open-loop cutoff frequency of the op amp isa. 10 Hzb. 20 Hzc. 50 Hzd. 100 Hz

The initial slope of a sine wave increases whena. Frequency decreasesb. Peak value increasesc. Cc increasesd. Slew rate decreases

If the frequency is greater than the power bandwidth,a. Slew-rate distortion occursb. A normal output signal occursc. Output offset voltage increasesd. Distortion may occur

An op amp has an open base resistor. The output voltage will bea. Zerob. Slightly different from zeroc. Maximum positive or negatived. An amplified sine wave

An op amp has a voltage gain of 500,000. If the output voltage is 1 V, the input voltage isa. 2 microvoltsb. 5 mVc. 10 mVd. 1 V

A 741C has supply voltages of plus and minus 15 V. If the load resistance is large, the MPP value isa. 0b. +15 Vc. 27 Vd. 30 V

Above the cutoff frequency, the voltage gain of a 741C decreases approximatelya. 10 dB per decadeb. 20 dB per octavec. 10 dB per octaved. 20 dB per decade

The voltage gain of an op amp is unity at thea. Cutoff frequencyb. Unity-gain frequencyc. Generator frequencyd. Power bandwidth

When slew-rate distortion of a sine wave occurs, the outputa. Is largerb. Appears triangularc. Is normald. Has no offset

A 741C hasa. A voltage gain of 100,000b. An input impedance of 2 Mohmc. An output impedance of 75 ohmd. All of the above

The closed-loop voltage gain of an inverting amplifier equalsa. The ratio of the input resistance to the feedback resistanceb. The open-loop voltage gainc. The feedback resistance divided by the input resistanced. The input resistance

The noninverting amplifier has aa. Large closed-loop voltage gainb. Small open-loop voltage gainc. Large closed-loop input impedanced. Large closed-loop output impedance

The voltage follower has aa. Closed-loop voltage gain of unityb. Small open-loop voltage gainc. Closed-loop bandwidth of zerod. Large closed-loop output impedance

A summing amplifier can havea. No more than two input signalsb. Two or more input signalsc. A closed-loop input impedance of infinityd. A small open-loop voltage gain

With negative feedback, the returning signala. Aids the input signalb. Opposes the input signalc. Is proportional to output currentd. Is proportional to differential voltage gain

How many types of negative feedback are there?a. One b. Two c. Three d. Four

A VCVS amplifier approximates an ideala. Voltage amplifierb. Current-to-voltage converterc. Voltage-to-current converterd. Current amplifier

The voltage between the input terminals of an ideal op amp isa. Zerob. Very smallc. Very larged. Equal to the input voltage

When an op amp is not saturated, the voltages at the noninverting and inverting inputs area. Almost equalb. Much differentc. Equal to the output voltaged. Equal to +15 V

The feedback fraction Ba. Is always less than 1b. Is usually greater than 1c. May equal 1

d. May not equal 1

An ICVS amplifier has no output voltage. A possible trouble isa. No negative supply voltageb. Shorted feedback resistorc. No feedback voltaged. Open load resistor

In a VCVS amplifier, any decrease in open-loop voltage gain produces an increase ina. Output voltage b. Error voltage c. Feedback voltaged. Input voltage

The open-loop voltage gain equals thea. Gain with negative feedbackb. Differential voltage gain of the op ampc. Gain when B is 1d. Gain at funity

The loop gain AOLBa. Is usually much smaller than 1b. Is usually much greater than 1c. May not equal 1d. Is between 0 and 1

The closed-loop input impedance with an ICVS amplifier isa. Usually larger than the open-loop input impedanceb. Equal to the open-loop input impedancec. Sometimes less than the open-loop impedanced. Ideally zero

With an ICVS amplifier, the circuit approximates an ideala. Voltage amplifierb. Current-to-voltage converterc. Voltage-to-current converterd. Current amplifier

Negative feedback reduces thea. Feedback fractionb. Distortionc. Input offset voltaged. Loop gain

A voltage follower has a voltage gain ofa. Much less than 1b. 1c. More than 1d. A

The voltage between the input terminals of a real op amp isa. Zerob. Very smallc. Very larged. Equal to the input voltage

The transresistance of an amplifier is the ratio of itsa. Output current to input voltageb. Input voltage to output currentc. Output voltage to input voltaged. Output voltage to input current

Current cannot flow to ground througha. A mechanical groundb. An ac groundc. A virtual groundd. An ordinary ground

In a current-to-voltage converter, the input current flowsa. Through the input impedance of the op ampb. Through the feedback resistorc. To groundd. Through the load resistor

The input impedance of a current-to-voltage converter is

a. Smallb. Largec. Ideally zerod. Ideally infinite

The open-loop bandwidth equalsa. funity b. f2(OL) c. funity/ACLd. fmax

The closed-loop bandwidth equalsa. funity b. f2(OL)c. funity/ACLd. fmax

For a given op amp, which of these is constant?a. f2(CL)b. Feedback voltagec. ACLd. ACLf2(CL)

Negative feedback does not improvea. Stability of voltage gainb. Nonlinear distortion in later stagesc. Output offset voltaged. Power bandwidth

An ICVS amplifier is saturated. A possible trouble isa. No supply voltagesb. Open feedback resistorc. No input voltaged. Open load resistor

A VCVS amplifier has no output voltage. A possible trouble isa. Shorted load resistorb. Open feedback resistorc. Excessive input voltaged. Open load resistor

An ICIS amplifier is saturated. A possible trouble isa. Shorted load resistorb. R2 is openc. No input voltaged. Open load resistor

An ICVS amplifier has no output voltage. A possible trouble isa. No positive supply voltageb. Open feedback resistorc. No feedback voltaged. Shorted load resistor

The closed-loop input impedance in a VCVS amplifier isa. Usually larger than the open-loop input impedanceb. Equal to the open-loop input impedancec. Sometimes less than the open-loop input impedanced. Ideally zero

In a linear op-amp circuit, thea. Signals are always sine wavesb. Op amp does not go into saturationc. Input impedance is ideally infinited. Gain-bandwidth product is constant

In an ac amplifier using an op amp with coupling and bypass capacitors, the output offset voltage isa. Zerob. Minimumc. Maximumd. Unchanged

To use an op amp, you need at leasta. One supply voltageb. Two supply voltages

c. One coupling capacitord. One bypass capacitor

In a controlled current source with op amps, the circuit acts like aa. Voltage amplifierb. Current-to-voltage converterc. Voltage-to-current converterd. Current amplifier

An instrumentation amplifier has a higha. Output impedanceb. Power gainc. CMRRd. Supply voltage

A current booster on the output of an op amp will increase the short-circuit current bya. ACLb. Beta dcc. funityd. Av

Given a voltage reference of +2.5 V, we can get a voltage reference of +15 V by using aa. Inverting amplifierb. Noninverting amplifierc. Differential amplifierd. Instrumentation amplifier

In a differential amplifier, the CMRR is limited mostly bya. CMRR of the op ampb. Gain-bandwidth productc. Supply voltagesd. Tolerance of resistors

The input signal for an instrumentation amplifier usually comes froma. An inverting amplifierb. A transducerc. A differential amplifierd. A Wheatstone bridge

In the classic three op-amp instrumentation amplifier, the differential voltage gain is usually produced by thea. First stageb. Second stagec. Mismatched resistorsd. Output op amp

Guard driving reduces thea. CMRR of an instrumentation amplifierb. Leakage current in the shielded cablec. Voltage gain of the first staged. Common-mode input voltage

In an averaging circuit, the input resistances area. Equal to the feedback resistanceb. Less than the feedback resistancec. Greater than the feedback resistanced. Unequal to each other

A D/A converter is an application of thea. Adjustable bandwidth circuitb. Noninverting amplifierc. Voltage-to-current converterd. Summing amplifier

In a voltage-controlled current source, a. A current booster is never usedb. The load is always floatedc. A stiff current source drives the loadd. The load current equals ISC

The Howland current source produces aa. Unidirectional floating load current

b. Bidirectional single-ended load currentc. Unidirectional single-ended load currentd. Bidirectional floating load current

The purpose of AGC is toa. Increase the voltage gain when the input signal increasesb. Convert voltage to currentc. Keep the output voltage almost constantd. Reduce the CMRR of the circuit

1 ppm is equivalent toa. 0.1%b. 0.01%c. 0.001%d. 0.0001%

An input transducer convertsa. Voltage to currentb. Current to voltagec. An electrical quantity to a nonelectrical quantityd. A nonelectrical quantity to an electrical quantity

A thermistor converts a. Light to resistanceb. Temperature to resistancec. Voltage to soundd. Current to voltage

When we trim a resistor, we area. Making a fine adjustmenta. Reducing its valueb. Increasing its valued. Making a coarse adjustment

A D/A converter with four inputs hasa. Two outputsb. Four outputsc. Eight outputsd. Sixteen outputs

An op amp with a rail-to-rail output a. Has a current-boosted outputb. Can swing all the way to either supply voltagec. Has a high output impedanced. Cannot be less than 0 V.

When a JFET is used in an AGC circuit, it acts like aa. Switchb. Voltage-controlled current sourcec. Voltage-controlled resistanced. Capacitance

If an op amp has only a positive supply voltage, its output cannota. Be negativeb. Be zeroc. Equal the supply voltaged. Be ac coupled

The region between the passband and the stopband is called thea. Attenuation b. Center c. Transition d. Ripple

The center frequency of a bandpass filter is always equal toa. The bandwidthb. Geometric average of the cutoff frequenciesc. Bandwidth divided by Qd. 3-dB frequency

The Q of a narrowband filter is alwaysa. smallb. equal to BW divided by f0c. less than 1d. greater than 1

A bandstop filter is sometimes called aa. Snubberb. Phase shifterc. Notch filterd. Time-delay circuit

The all-pass filter hasa. No passband b. One stopbandc. the same gain at all frequenciesd. a fast rolloff above cutoff

The approximation with a maximally-flat passband isa. Chebyshevb. Inverse Chebyshevc. Ellipticd. Bessel

The approximation with a rippled passband isa. Butterworthb. Inverse Chebyshevc. Ellipticd. Bessel

The approximation that distorts digital signals the least is thea. Butterworthb. Chebyshevc. Ellipticd. Bessel

If a filter has six second-order stages and one first-order stage, the order isa. 2b. 6c. 7d. 13

If a Butterworth filter has 9 second-order stages, its rolloff rate isa. 20 dB per decadeb. 40 dB per decadec. 180 dB per decaded. 360 dB per decade

If n = 10, the approximation with the fastest rolloff in the transition region isa. Butterworthb. Chebyshevc. Inverse Chebyshevd. Elliptic

The elliptic approximation has a a. Slow rolloff rate compared to the Cauerb. Rippled stopbandc. Maximally-flat passbandd. Monotonic stopband

Linear phase shift is equivalent toa. Q = 0.707b. Maximally-flat stopbandc. Constant time delayd. Rippled passband

The filter with the slowest rolloff rate is thea. Butterworthb. Chebyshevc. Ellipticd. Bessel

A first-order active-filter stage hasa. One capacitorb. Two op ampsc. Three resistorsd. a high Q

A first-order stage cannot have a

a. Butterworth responseb. Chebyshev responsec. Maximally-flat passbandd. Rolloff rate of 20 dB per decade

Sallen-Key filters are also calleda. VCVS filtersb. MFB filtersc. Biquadratic filtersd. State-variable filters

To build a 10th-order filter, we should cascadea. 10 first-stage stagesb. 5 second-order stagesc. 3 third-order stagesd. 2 fourth-order stages

To get a Butterworth response with an 8th-order filter, the stages need to have a. Equal Q'sb. Unequal center frequenciesc. Inductorsd. Staggered Q's

To get a Chebyshev response with a 12th-order filter, the stages need to havea. Equal Q'sb. Equal center frequenciesc. Staggered bandwidthsd. Staggered center frequencies and Q's

The Q of a Sallen-Key second-order stage depends on thea. Voltage gainb. Center frequencyc. Bandwidthd. GBW of the op amp

With Sallen-Key high-pass filters, the pole frequency must bea. Added to the K valuesb. Subtracted from the K valuesc. Multiplied by the K valuesd. Divided by the K values

If BW increases, thea. Center frequency decreasesb. Q decreasesc. Rolloff rate increasesd. Ripples appear in the stopband

When Q is greater than 1, a bandpass filter should be built witha. Low-pass and high-pass stagesb. MFB stagesc. Notch stagesd. All-pass stages

The all-pass filter is used when a. High rolloff rates are neededb. Phase shift is importantc. A maximally-flat passband is neededd. A rippled stopband is important

A second-order all-pass filter can vary the output phase froma. 90 degrees to -90 degreesb. 0 degrees to -180 degreesc. 0 degrees to -360 degreesd. 0 degrees to -720 degrees

The all-pass filter is sometimes called aa. Tow-Thomas filterb. Delay equalizerc. KHN filterd. State-variable filter

The biquadratic filter a. Has low component sensitivityb. Uses three or more op ampsc. Is also called Tow-Thomas filterd. All of the above

The state-variable filter a. Has a low-pass, high-pass, and bandpass outputb. Is difficult to tunec. Has high component sensitivityd. Uses less than three op amps

If GBW is limited, the Q of the stage willa. Remain the sameb. Doublec. Decreased. Increase

To correct for limited GBW, a designer may usea. A constant time delayb. Predistortionc. Linear phase shiftd. A rippled passband

In a nonlinear op-amp circuit, thea. Op amp never saturatesb. Feedback loop is never openedc. Output shape is the same as the input shaped. Op amp may saturate

To detect when the input is greater than a particular value, use aa. Comparatorb. Clamperc. Limiterd. Relaxation oscillator

The voltage out of a Schmitt trigger isa. A low voltageb. A high voltagec. Either a low or a high voltaged. A sine wave

Hysteresis prevents false triggering associated witha. A sinusoidal inputb. Noise voltagesc. Stray capacitancesd. Trip points

If the input is a rectangular pulse, the output of an integrator is aa. Sine waveb. Square wavec. Rampd. Rectangular pulse

When a large sine wave drives a Schmitt trigger, the output is aa. Rectangular waveb. Triangular wavec. Rectified sine waved. Series of ramps

If pulse width decreases and the period stays the same, the duty cyclea. Decreasesb. Stays the samec. Increasesd. Is zero

The output of a relaxation oscillator is aa. Sine waveb. Square wavec. Ramp d. Spike

If AOL = 200,000, the closed-loop knee voltage of a silicon diode isa. 1 uVb. 3.5 uVc. 7 uVd. 14 uV

The input to a peak detector is a triangular wave with a peak-to-peak value of 8 V and an average value of 0. The output isa. 0 b. 4 V

c. 8 V d. 16 V

The input voltage to a positive limiter is a triangular wave of 8 V pp and an average value of 0. If the reference level is 2 V, the output isa. 0b. 2 Vpp c. 6 Vpp d. 8 Vpp

The discharging time constant of a peak detector is 10 ms. The lowest frequency you should use isa.10 Hz b.100 Hz c. 1 kHz d. 10 kHz

A comparator with a trip point of zero is sometimes called aa. Threshold detectorb. Zero-crossing detectorc. Positive limit detectord. Half-wave detector

To work properly, many IC comparators need an externala. Compensating capacitorb. Pullup resistorc. Bypass circuitd. Output stage

A Schmitt trigger usesa. Positive feedbackb. Negative feedbackc. Compensating capacitorsd. Pullup resistors

A Schmitt triggera. Is a zero-crossing detectorb. Has two trip pointsc. Produces triangular output wavesd. Is designed to trigger on noise voltage

A relaxation oscillator depends on the charging of a capacitor through aa. Resistor b. Inductor c. Capacitor d. Noninverting input

A ramp of voltagea. Always increasesb. Is a rectangular pulsec. Increases or decreases at a linear rated. Is produced by hysteresis

The op-amp integrator usesa. Inductorsb. The Miller effectc. Sinusoidal inputsd. Hysteresis

The trip point of a comparator is the input voltage that causesa. The circuit to oscillateb. Peak detection of the input signalc. The output to switch statesd. Clamping to occur

In an op-amp integrator, the current through the input resistor flows into thea. Inverting inputb. Noninverting inputc. Bypass capacitord. Feedback capacitor

An active half-wave rectifier has a knee voltage ofa. VK

b. 0.7 V c. More than 0.7 Vd. Much less than 0.7 V

In an active peak detector, the discharging time constant isa. Much longer than the periodb. Much shorter than the periodc. Equal to the periodd. The same as the charging time constant

If the reference voltage is zero, the output of an active positive limiter isa. Positiveb. Negativec. Either positive or negatived. A ramp

The output of an active positive clamper isa. Positiveb. Negativec. Either positive or negatived. A ramp

The positive clamper addsa. A positive dc voltage to the inputb. A negative dc voltage to the inputc. An ac signal to the outputd. A trip point to the input

A window comparatora. Has only one usable thresholdb. Uses hysteresis to speed up responsec. Clamps the input positively d. Detects an input voltage between two limits

An oscillator always needs an amplifier witha. Positive feedbackb. Negative feedbackc. Both types of feedbackd. An LC tank circuit

The voltage that starts an oscillator is caused bya. Ripple from the power supplyb. Noise voltage in resistorsc. The input signal from a generatord. Positive feedback

The Wien-bridge oscillator is usefula. At low frequenciesb. At high frequenciesc. With LC tank circuitsd. At small input signals

A lag circuit has a phase angle that isa. Between 0 and +90 degreesb. Greater than 90 degreesc. Between 0 and -90 degreesd. The same as the input voltage

A coupling circuit is aa. Lag circuitb. Lead circuitc. Lead-lag circuitd. Resonant circuit

A lead circuit has a phase angle that isa. Between 0 and +90 degreesb. Greater than 90 degreesc. Between 0 and -90 degreesd. The same as the input voltage

A Wien-bridge oscillator usesa. Positive feedbackb. Negative feedbackc. Both types of feedbackd. An LC tank circuit

Initially, the loop gain of a Wien-bridge oscillator is

a. 0b. 1c. Lowd. High

A Wien bridge is sometimes called aa. Notch filterb. Twin-T oscillatorc. Phase shifterd. Wheatstone bridge

To vary the frequency of a Wien bridge, you can varya. One resistorb. Two resistorsc. Three resistorsd. One capacitor

The phase-shift oscillator usually hasa. Two lead or lag circuitsb. Three lead or fag circuitsc. A lead-lag circuitd. A twin-T filter

For oscillations to start in a circuit, the loop gain must be greater than 1 when the phase shift around the loop isa. 90 degreesb. 180 degreesc. 270 degreesd. 360 degrees

The most widely used LC oscillator is thea. Armstrongb. ClappC. Colpittsd. Hartley

Heavy feedback in an LC oscillatora. Prevents the circuit from startingb. Causes saturation and cutoffc. Produces maximum output voltaged. Means B is small

When Q decreases in a Colpitts oscillator, the frequency of oscillationa. Decreasesb. Remains the samec. Increasesd. Becomes erratic

Link coupling refers toa. Capacitive couplingb. Transformer couplingc. Resistive couplingd. Power coupling

The Hartley oscillator usesa. Negative feedbackb. Two inductorsc. A tungsten lampd. A tickler coil

To vary the frequency of an LC oscillator, you can varya. One resistorb. Two resistorsc. Three resistorsd. One capacitor

Of the following, the one with the most stable frequency is thea. Armstrongb. Clappc. Colpittsd. Hartley

The material with the piezoelectric effect isa. Quartz b. Rochelle salts c. Tourmalined. All the above

Crystals have a verya. Low Q b. High Q c. Small inductance d. Large resistance

The series and parallel resonant frequencies of a crystal area. Very close togetherb. Very far apartc. Equald. Low frequencies

The kind of oscillator found in an electronic wristwatch is thea. Armstrongb. Clappc. Colpittsd. Quartz crystal

A monostable 555 timer has the following number of stable states:a. 0b. 1c. 2d. 3

An astable 555 timer has the following number of stable states:a. 0b. 1c. 2d. 3

The pulse width out of a one-shot multivibrator increases when thea. Supply voltage increasesb. Timing resistor decreasesc. UTP decreasesd. Timing capacitance increases

The output waveform of a 555 timer isa. sinusoidalb. triangularc. rectangulard. elliptical

The quantity that remains constant in a pulse-width modulator isa. Pulse widthb. Periodc. Duty cycled. Space

The quantity that remains constant in a pulse-position modulator isa. Pulse widthb. Periodc. Duty cycled. Space

When a PLL is locked on the input frequency, the VCO frequencya. Is less than f0b. Is greater than f0c. Equals f0d. Equals fin

The bandwidth of the low-pass filter in a PLL determines thea. Capture rangeb. Lock rangec. Free-running frequencyd. Phase difference

Voltage regulators normally usea. Negative feedbackb. Positive feedbackc. No feedbackd. Phase limiting

During regulation, the power dissipation of the pass transistor equals the collector-emitter voltage times thea. Base currentb. Load currentc. Zener current

d. Foldback current

Without current limiting, a shorted load will probablya. Produce zero load currentb. Destroy diodes and transistorsc. Have a load voltage equal to the zener voltaged. Have too little load current

A current-sensing resistor is usuallya. Zerob. Smallc. Larged. Open

Simple current limiting produces too much heat in thea. Zener diode b. Load resistor c. Pass transistord. Ambient airWith foldback current limiting, the load voltage approaches zero, and the load current approachesa. A small value b. Infinity c. The zener current d. A destructive level

A capacitor may be needed in a discrete voltage regulator to preventa. Negative feedbackb. Excessive load currentc. Oscillationsd. Current sensing

If the output of a voltage regulator varies from 15 to 14.7 V between the minimum and maximum load current, the load regulation isa. 0 b. 1% c. 2% d. 5%

If the output of a voltage regulator varies from 20 to 19.8 V when the line voltage varies over its specified range, the source regulation isa. 0 b. 1% c. 2% d. 5%

The output impedance of a voltage regulator isa. Very smallb. Very largec. Equal to the load voltage divided by the load currentd. Equal to the input voltage divided by the output current

Compared to the ripple into a voltage regulator, the ripple out of a voltage regulator isa. Equal in valueb. Much largerc. Much smallerd. Impossible to determine

A voltage regulator has a ripple rejection of -60 dB. If the input ripple is 1 V, the output ripple is a. -60 mV b. 1 mVc. 10 mVd. 1000 V

Thermal shutdown occurs in an IC regulator ifa. Power dissipation is too highb. Internal temperature is too highc. Current through the device is too highd. All the above occur

If a linear three-terminal IC regulator is more than a few inches from the filter capacitor, you may get oscillations inside the IC unless you usea. Current limitingb. A bypass capacitor on the input pinc. A coupling capacitor on the output pind. A regulated input voltage

The 78XX series of voltage regulators produces an output voltage that isa. Positive b. Negativec. Either positive or negatived. Unregulated

The 78XX-12 produces a regulated output voltage of a. 3 V b. 4 Vc. 12 Vd. 40 V

A current booster is a transistor ina. Series with the IC regulatorb. Parallel with the IC regulatorc. Either series or paralleld. Shunt with the load

To turn on a current booster, we can drive its base-emitter terminals with the voltage acrossa. A load resistorb. A zener impedancec. Another transistord. A current-sensing resistor

A phase splitter produces two output voltages that area. Equal in phaseb. Unequal in amplitudec. Opposite in phased. Very small

A series regulator is an example of aa. Linear regulatorb. Switching regulatorc. Shunt regulatord. Dc-to-dc converter

To get more output voltage from a buck switching regulator, you have toa. Decrease the duty cycleb. Decrease the input voltagec. Increase the duty cycled. Increase the switching frequency

An increase of line voltage into a power supply usually producesa. A decrease in load resistanceb. An increase in load voltagec. A decrease in efficiencyd. Less power dissipation in the rectifier diodes

A power supply with low output impedance has lowa. Load regulationb. Current limitingc. Line regulationd. Efficiency

A zener-diode regulator is a a. Shunt regulatorb. Series regulatorc. Switching regulatord. Zener follower

The input current to a shunt regulator is a. Variableb. Constantc. Equal to load currentd. Used to store energy in a magnetic field

An advantage of shunt regulation is a. Built-in short-circuit protectionb. Low power dissipation in the pass transistorc. High efficiencyd. Little wasted power

The efficiency of a voltage regulator is high when a. Input power is lowb. Output power is highc. Little power is wastedd. Input power is high

A shunt regulator is inefficient because a. It wastes powerb. It uses a series resistor and a shunt transistorc. The ratio of output to input power is lowd. All of the above

A switching regulator is considereda. Quietb. Noisyc. Inefficientd. Linear

The zener follower is an example of a a. Boost regulatorb. Shunt regulatorc. Buck regulatord. Series regulator

A series regulator is more efficient than a shunt regulator becausea. It has a series resistorb. It can boost the voltagec. The pass transistor replaces the series resistord. It switches the pass transistor on and off

The efficiency of a linear regulator is high when thea. Headroom voltage is lowb. Pass transistor has high power dissipationc. Zener voltage is lowd. Output voltage is low

If the load is shorted, the pass transistor has the least power dissipation when the regulator hasa. Foldback limitingb. Low efficiencyc. Buck topologyd. A high zener voltage

The dropout voltage of standard monolithic linear regulators is closest toa. 0.3 Vb. 0.7 Vc. 2 Vd. 3.1 V

In a buck regulator, the output voltage is filtered with aa. Choke-input filterb. Capacitor-input filterc. Dioded. Voltage divider

The regulator with the highest efficiency is thea. Shunt regulatorb. Series regulatorc. Switching regulatord. Dc-to-dc converter

In a boost regulator, the output voltage is filtered with aa. Choke-input filterb. Capacitor-input filterc. Dioded. Voltage divider

The buck-boost regulator is alsoa. A step-down regulatorb. A step-up regulatorc. An inverting regulatord. All of the above