Basic Electronics and Computer Fundamentals MCQs

Multiple Choice Questions 21 Pages

Mahatma Gandhi University

BSc Computer Science

MPC

Contributed by

Manpreet Prasad Chaudhuri

CORE I - BASIC ELECTRONICS AND COMPUTER FUNDAMENTALS
For BSc Computer Science Off Campus Stream

1. The advantage of transistor over vacuum tube is
1. No heat is required
2. Small size and light in weight
3. Very low power consumption
4. All of the above

2. Aging effect exists in
1. Vacuum tubes only
2. Transistors only
3. Both vacuum tubes as well as transistors
4. None of the above

3. A collector collects
1. Electrons from the base in case of PNP transistor
2. Electrons from the emitter in case PNP transistor
3. Holes from the base in case of NPN transistor
4. Holes from the base in case of PNP transistor

4. In a PNP transistor, with normal bias
1. The collector junction has negligible resistance
2. Only holes cross the collector junction
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3. The collector –base junction in reverse biased and the emitter base junction is forward
biased
4. Only majority carriers cross the collector junction

5. A PNP transistor is made of
1. Silicon
2. Germanium
3. Either silicon or germanium
4. None of the above

6. In most transistors, the collector region is made physically larger than the emitter region
1. for dissipating heat
2. to distinguish it form other regions
3. as it is sensitive to ultra-violet rays
4. to reduce resistance in the path of flow of electrons

7. In a transistor which of the following region is very lightly doped and is very thin
1. Emitter
2. Base
3. Collector
4. None of the above

8. In a NPN transistor the function of the emitter is
1. To emit or inject holes into the collector
2. To emit or inject electrons into the collector
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3. To emit or inject electrons into the base
4. To emit or inject holes into the base

9. In a PNP transistor, with normal bias, the emitter junction
1. is always reverse biased
2. offers very high resistance
3. offers a low resistance
4. remains open

10. In a NPN transistor, when emitter junction is forward biased and collector junction is reverse
biased, the transistor will operate in
1. Active region
2. Saturation region
3. Cut off region
4. Inverted region

11. A transistor will operate in inverted region when
1. Emitter junction is forward biased and collector junction is reverse biased
2. Emitter junction is reverse biased and collector junction is forward biased
3. Emitter junction as well as collector junction are forward biased
4. Emitter junction as well as collector junction are reverse biased

12. In a PNP transistor, electrons flow
1. Into the transistor as the collector only
2. Into the transistor at the base and the collector leads
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3. Out of the transistor at base and collector leads
4. Out of the transistor at base collector as well as emitter leads

13. Which of the following statement is correct
1. FET and junction transistor both are unipolar
2. FET and junction transistor both are bipolar
3. The FET is bipolar, while junction transistors are unipolar
4. The FET is unipolar, while junction transistors are bipolar

14. Most small signal transistors are
1. NPN, silicon, in a plastic package
2. PNP, silicon, ina plastic package
3. NPN, germanium in a metallic case
4. PNP, germanium in a metallic case

15. A transistor may fail due to
1. Open weld at the wire leads to the semiconductor
2. Short circuit caused by momentary overloads
3. Overheating due to circuit failures
4. Any of the above

16. The transistor is usually encapsuled in
1. Graphite powder
2. Enamel point
3. Epoxy resin
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4. Any of the above

17. Arrow head on a transistor symbol indicates
1. Direction of electron current in emitter
2. Direction of hole current in emitter
3. Diffusion current in emitter
4. Drift current in emitter

18. Power transistors are invariably provided with
1. Soldered connections
2. Heat sink
3. Metallic casing
4. None of the above

19. The heat sink disposes off heat mainly by
1. Radiation
2. Natural convection
3. Forced convection
4. Conduction

20. Largest current flow of a bipolar transistor occurs
1. In emitter
2. In base
3. In collector
4. Through emitter-collector
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21. Conventional biasing of a bipolar transistor has
1. EB forward biased and CB forward biased
2. EB reversed biased and CB forward biased
3. EB forward biased and CB reverse biased
4. EB reversed biased and CB reverse biased

22. Which of the following number specification refers to FET with one gate
1. 2N
2. 3N
3. 3Y
4. 3X

23. In a NPN transistor if the emitter junction is reverse biased and collector junction is also
reversed biased, he transistor will operate in
1. Active region
2. Saturation region
3. Cut-off region
4. Inverted region

24. In a normally biased NPN transistor the main current crossing the collector junction is
1. A drift current
2. A hole current
3. A diffusion current
4. Same as the base current
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25. A transistor has
1. Collector
2. Emitter
3. Base

26. A diac is a semi-conductor device which acts as a
1. 2 terminal unidirectional switch
2. 2 terminal bidirectional switch
3. 3 terminal bidirectional switch
4. 4 terminal multi-directional switch

27. In a NPN transistor, when emitter junction is forward biased and collector junction is reverse
biased the transistor will operate in
1. Active region
2. Saturation region
3. Cut-off region
4. Inverted region

28. Which of the following is necessary for transistor action
1. The base region must be very wide
2. The base region must be very narrow
3. The base region must be made of some insulating material
4. The collector region must be heavily doped

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29. A triac is a semi-conductor device which acts as a
1. 2 terminal unidirectional switch
2. 2 terminal bidirectional switch
3. 3 terminal bidirectional switch
4. 4 terminal multi-directional switch

30. Which of the amplifier circuits using junction transistors has the best gain
1. Common emitter
2. Common base
3. Common collector
4. All above has the same gain

31. Which circuit has its output signal from the emitter
1. Common base
2. Common emitter
3. Emitter follower
4. None of the above

32. In a transistor with normal bias
1. The emitter junction has a low resistance
2. The emitter junction has a very high resistance
3. The emitter junction supplies majority carriers into the base region
4. None of the above

33. In a PNP transistor the electron flow into the transistor at
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1. I only
2. II only
3 II and III only
4. I and III only

34. In a PNP junction transistor as compared to base region the emitter region is more heavily
doped so that
1. Leakage current is minimized
2. Recombination will be increased in the base region
3. The flow across the base regional is only because of electrons
4. The flow across the base region is mainly because of holes

35. In a transistor leakage current mainly depends on
1. Doping of base
2. size of emitter
3. Rating of transistor
4. Temperature

36. Thermal run away of a transistor occurs when
1. Heat dissipation from transistor is excessive
2. Transistor joints melt due to high temperature
3. There is excessive leakage current due to temperature rise
4. None of the above

37. The leakage current in CB configuration may be around
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1. Few microamperes
2. Few hundred microamperes
3. Few milliamperes
4. Few hundred milliamperes

38. The input and output signals for CE amplifier are always
1. Equal
2. Inphase
3. Out of phase
4. Complementary to each other

39. As compared to a CB amplifier, a CE amplifier has
1. Lower current amplification
2. Higher current amplification
3. Lower input resistance
4. Higher input resistance

40. Which junction transistor is preferred for high input an low output impedance
1. Common emitter
2. Common base
3. Common collector
4. Any of the above

41. Common base configuration is little used because
1. It has low input impedance
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Basic Electronics and Computer Fundamentals MCQs

Basic Electronics and Computer Fundamentals MCQs

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