300+ TOP TRANSISTORS Questions and Answers pdf | MCQs

TRANSISTORS Questions and Answers pdf :-

1. A transistor has …………………

1. one pn junction
2. two pn junctions
3. three pn junctions
4. four pn junctions
ANS : 2

2. The number of depletion layers in a transistor is …………

four
three
one
two
ANS : 4

3. The base of a transistor is ………….. doped

heavily
moderately
lightly
none of the above
ANS : 3

4. The element that has the biggest size in a transistor is ………………..

collector
base
emitter
collector-base-junction
ANS : 1

5. In a pnp transistor, the current carriers are ………….

acceptor ions
donor ions
free electrons
holes
ANS : 4

6. The collector of a transistor is …………. doped

heavily
moderately
lightly
none of the above
ANS : 2

7. A transistor is a …………… operated device

current
voltage
both voltage and current
none of the above
ANS : 1

8. In a npn transistor, ……………. are the minority carriers

free electrons
holes
donor ions
acceptor ions
ANS : 2

9. The emitter of a transistor is ………………… doped

lightly
heavily
moderately
none of the above
ANS : 2

10. In a transistor, the base current is about ………….. of emitter current

25%
20%
35 %
5%
ANS : 4

11. At the base-emitter junctions of a transistor, one finds ……………

a reverse bias
a wide depletion layer
low resistance
none of the above
ANS : 3

12. The input impedance of a transistor is ………….

high
low
very high
almost zero
ANS : 2

13. Most of the majority carriers from the emitter ………………..

recombine in the base
recombine in the emitter
pass through the base region to the collector
none of the above
ANS :3

14. The current IB is …………

electron current
hole current
donor ion current
acceptor ion current
ANS : 1

15. In a transistor ………………..

IC = IE + IB

IB = IC + IE

IE = IC – IB

IE = IC + IB

ANS : 4

16. The value of a of a transistor is ……….

more than 1
less than 1
1
none of the above
ANS : 2

17. IC = aIE + ………….

IB
ICEO
ICBO
ßIB
ANS : 3

18. The output impedance of a transistor is ……………..

high
zero
low
very low
ANS : 1

19. In a tansistor, IC = 100 mA and IE = 100.2 mA. The value of ß is …………

100
50
about 1
200
ANS : 4

20. In a transistor if ß = 100 and collector current is 10 mA, then IE is …………

100 mA
100.1 mA
110 mA
none of the above
ANS : 2

21. The relation between ß and a is …………..

ß = 1 / (1 – a )
ß = (1 – a ) / a
ß = a / (1 – a )
ß = a / (1 + a )
ANS : 3

22. The value of ß for a transistor is generally ………………..

1
less than 1
between 20 and 500
above 500
ANS : 3

23. The most commonly used transistor arrangement is …………… arrangement

common emitter
common base
common collector
none of the above
ANS : 1

24. The input impedance of a transistor connected in …………….. arrangement is the highest

common emitter
common collector
common base
none of the above
ANS : 2

25. The output impedance of a transistor connected in ……………. arrangement is the highest

common emitter
common collector
common base
none of the above
ANS : 3

26. The phase difference between the input and output voltages in a common base arrangement is …………….

180o
90o
270o
0o
ANS : 4

27. The power gain in a transistor connected in ……………. arrangement is the highest

common emitter
common base
common collector
none of the above
ANS : 1

28. The phase difference between the input and output voltages of a transistor connected in common emitter arrangement is ………………

0o
180o
90o
270o
ANS : 2

29. The voltage gain in a transistor connected in ………………. arrangement is the highest

common base
common collector
common emitter
none of the above
ANS : 3

30. As the temperature of a transistor goes up, the base-emitter resistance ……………

decreases
increases
remains the same
none of the above
ANS : 1

31. The voltage gain of a transistor connected in common collector arrangement is ………..

equal to 1
more than 10
more than 100
less than 1
ANS : 4

32. The phase difference between the input and output voltages of a transistor connected in common collector arrangement is ………………

180o
0o
90o
270o
ANS : 2

33. IC = ß IB + ………..

ICBO
IC
ICEO
aIE
ANS : 3

34. IC = [a / (1 – a )] IB + ………….

ICEO
ICBO
IC
(1 – a ) IB
ANS : 1

35. IC = [a / (1 – a )] IB + […….. / (1 – a )]

ICBO
ICEO
IC
IE
ANS : 1

36. BC 147 transistor indicates that it is made of …………..

germanium
silicon
carbon
none of the above
ANS : 2

37. ICEO = (………) ICBO

ß
1 + a
1 + ß
none of the above
ANS : 3

38. A transistor is connected in CB mode. If it is not connected in CE mode with same bias voltages, the values of IE, IB and IC will …………..

remain the same
increase
decrease
none of the above
ANS : 1

39. If the value of a is 0.9, then value of ß is ………..

9
0.9
900
90
ANS : 4

40. In a transistor, signal is transferred from a …………… circuit

high resistance to low resistance
low resistance to high resistance
high resistance to high resistance
low resistance to low resistance
ANS : 2

41. The arrow in the symbol of a transistor indicates the direction of ………….

electron current in the emitter
electron current in the collector
hole current in the emitter
donor ion current
ANS : 3

42. The leakage current in CE arrangement is ……………. that in CB arrangement

more than
less than
the same as
none of the above
ANS : 1

43. A heat sink is generally used with a transistor to …………

increase the forward current
decrease the forward current
compensate for excessive doping
prevent excessive temperature rise
ANS : 4

44. The most commonly used semiconductor in the manufacture of a transistor is ………….

germanium
silicon
carbon
none of the above
ANS : 2

45. The collector-base junction in a transistor has ……………..

forward bias at all times
reverse bias at all times
low resistance
none of the above
ANS : 2

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