Malvino Chapter 6 With Answers Electronics ECE Board Exam

Malvino Chapter 6 With Answers Electronics ECE Board Exam




1. A transistor has how many doped regions?

a. 1
b. 2                       
c. 3                     
d. 4
c

2. What is one important thing transistors do?

a. Amplify weak signals
b. Rectify line voltage
C. Regulate voltage
d. Emit light
a

3. Who invented the first junction transistor?

a. Bell
b. Faraday
c. Marconi
d. Schockley
d

4. In an npn transistor, the majority carriers in the base are

a. Free electrons
b. Holes
c. Neither
d. Both
b

5. The barrier potential across each silicon depletion layer is

a. 0                      
b. 0.3 V
c. 0.7 V                  
d. 1 V
c





6. The emitter diode is usually

a. Forward-biased
b. Reverse-biased
c. Nonconducting
d. Operating in the breakdown region
a

7. For normal operation of the transistor, the collector diode has to be

a. Forward-biased
b. Reverse-biased
c. Nonconducting
d. Operating in the breakdown region
b

8. The base of an npn transistor is thin and

a. Heavily doped
b. Lightly doped
c. Metallic
d. Doped by a pentavalent material
b

9. Most of the electrons in the base of an npn transistor flow

a. Out of the base lead
b. Into the collector
c. Into the emitter
d. Into the base supply
b

10. Most of the electrons in the base of an npn transistor do not recombine because they

a. Have a long lifetime
b. Have a negative charge
c. Must flow a long way through the base
d. Flow out of the base
a

11. Most of the electrons that flow through the base will

a. Flow into the collector
b. Flow out of the base lead
c. Recombine with base holes
d. Recombine with collector holes
a

12. The current gain of a transistor is the ratio of the

a. Collector current to emitter current
b. Collector current to base current
c. Base current to collector current
d. Emitter current to collector current
b

13. Increasing the collector supply voltage will increase

a. Base current
b. Collector current
c. Emitter current
d.  None of the above
d



14. The fact that only a few holes are in the base region means the base is

a. Lightly doped
b. Heavily doped
c. Undoped
d. None of the above
a

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

a. Base-emitter junction
b. Base-collector junction
c. Collector-base junction
d. Recombination path
a

16. When a free electron recombines with a hole in the base region, the free electron becomes

a. Another free electron
b. A valence electron
c. A conduction-band electron
d. A majority carrier
b

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.
d

18. If the current gain is 200 and the collector current is 100 mA, the base current is

a. 0.5 mA                
b. 2 mA
c. 2 A                  
d. 20 A
a

19. The base-emitter voltage is usually

a. Less than the base supply voltage
b. Equal to the base supply voltage
c. More than the base supply voltage
d. Cannot answer
a

20. The collector-emitter voltage is usually

a. Less than the collector supply voltage
b. Equal to the collector supply voltage
c. More than the collector supply voltage
d. Cannot answer
a







21. The power dissipated by a transistor approximately equals the collector current times

a. Base-emitter voltage
b. Collector-emitter voltage
c. Base supply voltage
d. 0.7 V
b

22. A small collector current with zero base current is caused by the leakage current of the

a. Emitter diode
b. Collector diode
c. Base diode
d.  Transistor
b

23. A transistor acts like a diode and a

a. Voltage source
b. Current source
c. Resistance
d. Power supply
b

24. If the base current is 100 mA and the current gain is 30, the collector current is

a. 300 mA                   
b. 3 A
c. 3.33 A                      
d. 10 A
b

25. The base-emitter voltage of an ideal transistor is

a. 0                        
b. 0.3 V
c. 0.7 V                    
d. 1 V
a

26. If you recalculate the collector-emitter voltage with the second approximation, the answer will usually be

a. Smaller than the ideal value
b.. The same as the ideal value
c. Larger than the ideal value
d. Inaccurate
c

27. In the active region, the collector current is not changed significantly by

a. Base supply voltage
b. Base current
c. Current gain
d. Collector resistance
d

28. The base-emitter voltage of the second approximation is

a. 0                        
b. 0.3 V
c. 0.7 V                    
d. 1 V
c
29. If the base resistor is open, what is the collector cuffent?

a. 0                        
b. 1 mA
c. 2 mA                     
d. 10 mA
a

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