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
1. Transistor is a _________ terminal device.
a. Two
b. Three
c. Four
d. both (a. and (b.
Ans: b
2. The three terminals of transistor are:
a. Gate, collector and emitter
b. Collector, base and source
c. Base, collector and emitter
d. Base, gate and collector
Ans: c
3. The transistor means ______ .
a. transfer resistor
b. trans resistor
c. tri resistor
d. none of the above
Ans: a
4. BJT is a ______ device.
a. unipolar
b. bipolar
c. multipolar d. both b and c
Ans: b
5. In Unipolar transistor, the current conduction is due to _________ .
a. minority carriers
b. majority carriers
c. both minority and majority carriers
d. all of the above
Ans: b
6. In bipolar transistor, the current is due to
a. holes
b. electrons
c. both holes and electrons
d. all of the above
Ans: c
7. BJT IS __________ controlled device.
a. field
b. voltage
c. resistor
d. current
Ans: d
8. The types of bipolar junction transistors are
a. ppn,npn
b. pnp, npn
c. npp, ppn
d. nnp, pnp
Ans: b
9. The middle region of a transistor is called __
a. base
b. collector
c. emitter
d. none of the above
Ans: a
10. The process by which impurities are added to a pure semiconductor is
a. Diffusing
b. drift
c. doping
d. mixing
Ans: c
11. Base of the transistor is always ___ and ____ doped.
a. thick, lightly
b. thin, lightly
c. thin, heavily
d. none of the above
Ans: b
12. The collector of a transistor is ______ doped.
a. heavily
b. moderately
c. lightly
d. none of the above
Ans: a
13. In transistors the collector region is larger than the emitter region for ______.
a. better heat dissipation
b. higher value of ß
c. better amplification
d. all of the above
Ans: a
14. Doping concentration is highest in ________ of a BJT.
a. emitter region
b. collector region
c. base region
d. all of the above
Ans: a
15. The ______ region has highest thickness than all other regions in a BJT.
a. base
b. collector
c. emitter
d. all of the above
Ans: b
16. The arrow in the transistor symbol indicates the direction of ____.
a. conventional emitter current
b. electron current in emitter
c. supply current
d. both a and b
Ans: a
17. The arrow in the transistor symbol indicates _______ terminal.
a. base
b. collector
c. emitter
d. none of the above
Ans: c
18. Transistor has _______ pn junctions.
a. one
b. two
c. three
d. none of the above
Ans: b
19. The depletion region at emitter junction in an unbiased transistor extends more into the _____ region.
a. collector
b. base
c. emitter
d. none of the above
Ans: b
20. The depletion region at collector junction in an unbiased transistor extends more into the base region because it is _______ doped.
a. heavily
b. moderately
c. lightly
d. none of the above
Ans: c
21. Barrier voltage is _____ on the N side.
a. positive
b. negative
c. zero
d. none of the above
Ans: a
22. _______ of electrons and holes in the base region consists the base current.
a. Ionization
b. Recombinations
c. Thermal agitation
d. None of the above
Ans: b
23. ________ constitute the dominant current in a npn transistor.
a. Holes
b. Electrons
c. Both holes and electrons
d. none of the above
Ans: c
24. The current gain of a transistor is defined as the ratio of the collector current to the _____.
a. base current
b. emitter current
c. supply current
d. collector current
Ans: a
25. A transistor __________.
a. is similar to a relay in that it uses a small amount of current to
control a larger amount of current flow.
b. has three connections called the base, emitter and collector
c. is like a switch in that it is used to turn a circuit on and off
d. all of the above
Ans: d
26. The graph of current gain versus collector current indicates that the current gain _______.
a. is constant
b. varies slightly
c. varies significantly
d. equals the collector current divided by the base current
Ans: b
27. _______ is the highest current in any bipolar transistor.
a. IB
b. IC
c. IE
d. none of the above
Ans: c
28. The concentration of impurities in a transistor:
a. equal for emitter, base and collector
b. least for emitter region
c. largest for emitter region
d. largest for collector region
Ans: c
29. When NPN transistor is used as amplifier
a. electrons move from base to emitter
b. electrons move from emitter to base
c. electrons move from collector to base
d. holes move from base to emitter
Ans: b
30. The base is made thin and lightly doped because
a. about 95% of the charge carriers may cross
b. about 100% of the charge carriers may cross
c. the transistors can be saved from large currents
d. none of these
Ans: a
Before solving this questions I suggest you must read this basic electronics
