Bipolar Junction Transistor (BJT) MCQs of Basic electronics questions. This mcqs are useful in your university Sppu exams, placements exams, GATE and others.
Before solving this questions I suggest you must read this basic electronics
Click to read part 1
1. Base to emitter voltage in forward biased transistor decreases with the increase of
temperature at the following rate:
a. 2.5 mV/degree C
b. 25 mV/degree C
c. 0.25 mV/degree C
d. 0.6 mV/degree C
Ans: a
2. No. of depletion layers in a transistor are __
a. two
b. three
c. four
d. none of the above
Ans: a
3. The emitter of a transistor is _____ doped.
a. moderately b. heavily
c. lightly
Ans: b
4. The input impedance of a transistor is ____ as compared to MOSFET.
a. low
b. high
c. very high
d. none of above
Ans: a
5. In an NPN transistor, ______ are the minority carrier.
a. electron
b. holes
c. donor ions
d. acceptor ions
Ans: b
6. In a transistor _____.
a. IB=IC+IB
b. IC=IE+IB
c. IE=IC+IB
d. IE=IC-IB
Ans: c
7. The value of alpha of a transistor is ________.
a. 0
b. 1
c. more than 1
d. less than 1
Ans: d
8. The value of ß of a transistor is ________.
a. between 20 and 500
b. 1
c. less than 1
d. 0
Ans: a
9. Transistor biasing represents ____ condition.
a. ac
b. dc
c. both ac and dc
d. none of the above
Ans: b
10. Transistor biasing is generally provided by a ________.
a. biasing circuit
b. biasing battery
c. diode
d. none of the above
Ans: a
11. The point of intersection of DC and AC load lines represents _______.
a. current point
b. operating point
c. voltage gain
d. none of the above
Ans: b
12. The phase difference between the input and output voltage in a common base arrangement is ________.
a. 90
b. 180
c. 0
d. none of the above
Ans: c
13. The phase difference between the input and output voltage in a common emitter arrangement is ________.
a. 0
b. 180
c. 90
d. 270
Ans: b
14. The phase difference between the input and output voltage in a common collector arrangement is ________.
a. 0
b. 90
c. 180
d. 270
Ans: a
15. The early effect in a bipolar transistor is caused by:
a. Large collector-base reverse bias
b. base width modulation
c. large emitter-base forward bias
d. increase in junction temperature
Ans: b
16. The _____ current of a transistor is neither the largest nor the smallest.
a. Base
b. Collector
c. emitter
d. none of the above
Ans: b
17. Which of the following currents are nearly equal to each other?
a. IB and IC
b. IE and IC
c. IB and IE
d. Ib,IC and IE
Ans: b
18. For a properly biased transistor, let IC=10mA and Ie=10.2mA. What is the level of IB?
a. 0.2A
b. 200mA
c. 200μA
d. 20.2mA
Ans: c
19. Holes flow constitutes the dominant current in a _______ transistor.
a. npn
b. pnp
c. a and b
d. none of the above
Ans: b
20. When the collector current increases, what does the current gain do?
a. decreases
b. stays the same
c. increases
d. any of the above
Ans: c
21. When the base resistor increases, the collector voltage will probably ________.
a. decrease
b. stays the same
c. increase
d. do all of the above
Ans: c
22. If the base resistor is very small, the transistor will operate in the _______.
a. cut off region
b. active region
c. saturation region
d. all of the above
Ans: c
23. Ignoring the bulk resistance of the collector diode, the collector-emitter saturation voltage is _____.
a. 0V
b. a few tenths of a volt
c. 1V
d. supply voltage
Ans: a
24. For common base transistor teh numerical value is least for _______.
a. voltage gain
b. power gain
c. resistance gain
d. current gain
Ans: d
25. For operating in the active region, the emitter junction should be _____ biased and collector junction should be ____ biased in BJT.
a. forward, forward
b. reverse, reverse
c. forward, reverse
d. reverse, forward
Ans: c
26. The emitter junction is ____ biased for operating BJT in saturation region.
a. forward
b. reverse
c. zero
d. none of the above
Ans: a
27. In which region are both the collector-base and base-emitter junctions forward biased for BJT?
a. active
b. cut-off
c. saturation
d. all of the above
Ans: c
28. For the BJT to operate in the saturation region, the base-emitter juntion must be ______ biased and the base-collector junction must be ________.
a. forward, forward
b. forward, reverse
c. reverse, reverse
d. reverse, forward
Ans: a
29. At what region of operation is the base-emitter junction forward biased and the base-collector junction reverse biased for BJT?
a. saturation
b. linear or active
c. cut-off
d. none of the above
Ans: b
30. The transistor acts as an amplifier in the ______ region.
a. Cut off
b. Active
c. Saturation
d. None of the above
Ans: b
Before solving this questions I suggest you must read this basic electronics
