Chapter 61. A transistor has how many doped regions?a. 1b. 2c. 3d. 4

2. What is one important thing transistors do?a. Amplify weak signalsb. Rectify line voltageC. Regulate voltaged. Emit light

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

4. In an npn transistor, the majority carriers in the basearea. Free electronsb. Holesc. Neitherd. Both

5. The barrier potential across each silicon depletionlayer isa. 0b. 0.3 Vc. 0.7 Vd. 1 V

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

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

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

9. Most of the electrons in the base of an npn transistorflowa. Out of the base leadb. Into the collectorc. Into the emitterd. Into the base supply

10. Most of the electrons in the base of an npn transistordo not recombine because theya. Have a long lifetimeb. Have a negative chargec. Must flow a long way through the base

d. Flow out of the base

11. 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

12. 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

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

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

15. In a normally biased npn transistor, the electrons inthe emitter have enough energy to overcome the barrier potential of thea. Base-emitter junctionb. Base-collector junctionc. Collector-base junctiond. Recombination path

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

17. 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.

18. If the current gain is 200 and the collector current is100 mA, the base current isa. 0.5 mAb. 2 mAc. 2 Ad. 20 A

19. The base-emitter voltage is usuallya. Less than the base supply voltage

b. Equal to the base supply voltagec. More than the base supply voltaged. Cannot answer

20. 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

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

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

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

24. If the base current is 100 mA and the current gain is30, the collector current isa. 300 mAb. 3 Ac. 3.33 Ad. 10 A

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

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

27. In the active region, the collector current is notchanged significantly bya. Base supply voltageb. Base currentc. Current gaind. Collector resistance

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

d. 1 V

29. If the base resistor is open, what is the collectorcuffent?a. 0b. 1 mAc. 2 mAd. 10 mA

Chapter 71. 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

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

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

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

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

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

7. 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

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

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

10. 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

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

12. 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

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

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

15. If the collector resistor decreases to zero in a base biased circuit, the load line will becomea. Horizontalb. Verticalc. Uselessd. Flat

16. The collector current is 10 mA. If the current gain is100, the base current isa. 1 microampb. 10 microampc. 100 microampd. 1 mA

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

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

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

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

21. The first step in analyzing emitter-based circuits is tofind thea. Base currentb. Emitter voltagec. Emitter currentd. Collector current

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

23. If the emitter resistor is open, the collector voltage isa. Lowb. Highc. Unchangedd. Unknown

24. If the collector resistor is open, the collector voltage isa. Lowb. Highc. Unchangedd. Unknown

25. 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

26. If the emitter resistance decreases, the collectorvoltagea. Decreasesb. Stays the samec. Increasesd. Breaks down the transistor

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

Chapter 81. For emitter bias, the voltage across the emitter resistor is the same as the voltage between the emitter and thea. Baseb. Collectorc. Emitterd. Ground

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

3. 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

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

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

6. VDB has a stable Q point likea. Base biasb. Emitter biasc. Collector-feedback biasd. Emitter-feedback bias

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

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

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

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

d. Doubles

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

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

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

14. 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 currentgaind. Greatly affected by temperature changes

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

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

17. 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

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

19. If the emitter resistor opens with TSEB, the collector voltage willa. Decreaseb. Stay the samec. Increase slightly

d. Equal the collector supply voltage

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

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

22. The majority carriers in the emitter of a pnp transistor area. Holesb. Free electronsc. Trivalent atomsd. Pentavalent atoms

23. 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

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

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

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

Chapter 91. For dc, the current in a coupling circuit isa. Zerob. Maximumc. Minimumd. Average

2. The current in a coupling circuit for high frequencies isa. Zerob. Maximumc. Minimumd. Average

3. A coupling capacitor isa. A dc shortb. An ac openc. A dc open and an ac shortd. A dc short and an ac open

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

5. The capacitor that produces an ac ground is called aa. Bypass capacitorb. Coupling capacitorc. Dc opend. Ac open

6. The capacitors of a CE amplifier appeara. Open to acb. Shorted to dcc. Open to supply voltaged. Shorted to ac

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

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

9. When the ac base voltage is too large, the ac emittercurrent isa. Sinusoidalb. Constantc. Distortedd. Alternating

10. In a CE amplifier with a large input signal, thepositive 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

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

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

13. If the ac voltage across the emitter diode is 1 mVand the ac emitter current is 0.1 mA, the ac resistance ofthe emitter diode is

a. 1 ohmb. 10 ohmc. 100 ohmd. 1 kohm

14. A graph of ac emitter current versus ac base-emitter voltage applies to thea. Transistorb. Emitter diodec. Collector dioded. Power supply

15. The output voltage of a CE amplifier isa. Amplifiedb. Invertedc. 180 degrees out of phase with the inputd. All of the above

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

17. The voltage across the load resistor of a CE amplifier isa. Dc and acb. DC onlyc. AC onlyd. Neither dc nor ac

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

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

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