Monday, January 31, 2011

PSU EXAMS ELECTRONICS ENGINEETING PRACTICE QUESTIONS

1. An example for insulator

a) a.copper

b) aluminium

c) c.plastic

d) none of these

Ans: c

2. An example for semiconductor

a) copper

b) aluminium

c) mica

d) germanium

Ans:d

3. Forbidden gap is

a) gap between conduction band and valance band

b) gap between covalant band and valance band

c) gap between conduction band and energy band

d) none of these

Ans:a

4. In conductor, Forbidden gap is

a) large

b) very large

c) small

d) overlapped

Ans:d

5. In insulator, Forbidden gap is

a) large

b) very large

c) small

d) overlapped

Ans:b

6. In semiconductor, Forbidden gap is

a) small

b) large

c) zero

d) none of these

Ans:a

7. A pure semiconductor is

a) carbon

b) extrinsic semiconductor

c) zero semiconductor

d) intrinsic semiconductor

Ans:d

8.After the valley point UJT acts as

a.transister

b.amplifier

c.contoller

d.forward PN Diode

Ans:d

9.UJT used in

a.pulse generator

b. electric circuit

c.either (a)&(b)

d.none of these

Ans:a

10.Diac is used as

a.triggering device

b. pulse generator

c. amplifier

d.contoller

Ans:a

11.Triac is

a.Two transister device

b.two diodes device

c.two diacs device

d.two SCR device

Ans:d

12.When Gate current is equal to zero,SCR acts as

a.Diode

b.transister

c.PNPN Diode

d.none of these

Ans:c

13..Triac has

a.one terminal

b.two terminal

c.three terminal

d.four terminal

Ans:c

14.Terminals of SCR

a.gate,emitter

b.gate,base.collector

c.anode,cathode,gate

d.none of these

Ans:c

15. A term ‘holding current’ used in

a.Diode

b.transister

c.PNPN Diode

d.SCR

Ans:d

16. A term ‘Zener breakdown voltage’ used in

a.Zener Diode

b.transister

c.PNPN Diode

d.SCR

Ans:a

17.A term ‘intrinsic standoff ratio’ used in

a.Diode

b.UJT

c.PNPN Diode

d.SCR

Ans:b

18. A term ‘latching current’ used in

a.Diode

b.transister

c.PNPN Diode

d.SCR

Ans:d

19.Which one is used as triggering device

a.Diode

b.UJT

c.PNPN Diode

d.none of these

Ans:b

20.SCR is used as

a.pulse generator

b. amplifier

c.contoller

d.none of these

Ans:c

21. Majority carriers of P type material

(a) Electrons

(b) Holes

(c) Protons

(d) None of these

Ans:b

22. Minority carriers of N type material

(a) Electrons

(b) Holes

(c) Protons

(d) None of these

Ans:b

23. Minority carriers of P type material

(a) Electrons

(b) Holes

(c) Protons

(d) None of these

Ans:a

24. Terminals of diode

a.gate,emitter

b.gate,base.collector

c.anode,cathode,

d.none of these

Ans:c

25. Terminals of transistor

a.gate,emitter

b.gate,base.collector

c.anode,cathode,gate

d.base,emitter,collector

Ans:d

26.At room temperature, extrinsic semiconductor is

a)conductor

b)poor conductor

c)partially conductor

d)none of these

Ans:b

27.Which one is trivalent impurity

a)boron

b)antimony

c)silicon

d)none of these

Ans:a

28.Which one is pentavalent impurity

a)boron

b)antimony

c)silicon

d)none of these

Ans:b

29.Resistance of an ideal diode, resistance during reverse biasing

(a) Zero

(b) Unity

(c) Maximum

(d) infinite

Ans:d

30. In CB Configuration of transistor, the output impedance is

(a) High

(b) medium

(c) Low

(d) none of these

Ans:a

31. In CB Configuration of transistor, voltage gain is

(a) High

(b) medium

(c) Low

(d) none of these

Ans:a

32. In CB Configuration of transistor, current gain is

(a) High

(b) medium

(c) Low

(d) almost one

Ans:d

33. In CE Configuration of transistor, the input impedance is

(a) High

(b) medium

(c) Low

(d) none of these

Ans:b

34. In CE Configuration of transistor, the output impedance is

(a) High

(b) medium

(c) Low

(d) none of these

Ans:b

35. In CC Configuration of transistor, the output impedance is

(a) High

(b) medium

(c) Low

(d) none of these

Ans:c

36. An ideal diode resistance has———resistance during forward biasing

(a) Zero

(b) Unity

(c) Maximum

(d) Minimum

Ans:a

37. Transistor is used as

(a) Switch

(b) Amplifier

(c) Both (a) & (b)

(d) None of these

Ans:c

38. Majority carriers of N type material

(a) Electrons

(b) Holes

(c) Protons

(d) None of these

Ans:a

39. Which one is semiconductor

(a) Copper

(b) Mica

(c) Carbon

(d) Silicon

Ans:d

40. Transistor is ———–Device

(a) Bipolar

(b) Unipolar

(c) Constant current

(d) Constant voltage

Ans:a

41. Diode is used as

(a) Regulator

(b) Inverter

(c) Current Regulator

(d) Rectifier

Ans:d

42. Zener diode acts as

(a) Rectifier

(b) Regulator

(c) Inverter

(d) None of these

Ans:b

43. Diode is ———–Device

(a) Bipolar

(b) Unipolar

(c) Constant current

(d) Constant voltage

Ans:b

44. Which one is intrinsic semiconductor

(a) Copper

(b) Mica

(c) Carbon

(d) Silicon

Ans:d

45. Which one is conductor

(a) Copper

(b) Mica

(c) Carbon

(d) Silicon

Ans:a

46. Which one is insulator

(a) Copper

(b) Mica

(c) Carbon

(d) Silicon

Ans:b

47. Ripple factor for half wave rectifier

(a) 1.11

(b) 1.21

(c) 1.5

(d) 0.48

Ans:b

48. Ripple factor for full wave rectifier

(a) 1.11

(b) 1.21

(c) 1.5

(d) 0.48

Ans:d

49. Ripple factor for bridge wave rectifier

(a) 1.11

(b) 1.21

(c) 1.5

(d) 0.48

Ans:d

50. BJT is ———–Device

(a) Bipolar

(b) Unipolar

(c) Constant current

(d) Constant voltage

Ans:a

51. SCR is

(a) un controlled device

(b) Regulator

(c) controlled device

(d) None of these

Ans:c

52. In CB Configuration of transistor, the input impedance is

(a) High

(b) medium

(c) Low

(d) none of these

Ans:c

53. Diac is

(a) Unidirectional device

(b) Bidirectional device

(c) Constant device

(d) None of these

Ans:b

54. Other name of SCR

(a) Transistor

(b) Diode

(c) Thyristor

(d) Resistor

Ans:c

55. UJT terminals are

(a) Base 1,Base 2,Emitter

(b) Base 1, collector,Emitter

(c) Base 1,Base 2,Collector

(d) None of these

Ans:a

56.A term intrinsic standoff ratio used in

(a) diode

(b) transistor

(c) UJT

(d) None of these

Ans:c

57.Which one works on negative resistance region

(a) diode

(b) transistor

(c) UJT

(d) None of these

Ans:c

58.SCR maybe considered as

(a) two diode model

(b) transistor model

(c) two transistor model

(d) None of these

Ans:c

59. Semiconductor is

  1. conductor
  2. insulator
  3. either conductor or insulator
  4. none of these

Ans:c

60. An example for conductor

  1. copper
  2. mica
  3. plastic
  4. carbon

Ans:a

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