Semiconductors MCQ Questions Answers

1. When a transistor is driven to saturation, ideally, the Vce is _____.

2. Vacuum tubes are _____.

3. Which one is used to provide current in vacuum tubes?

4. Tuned amplifiers are used for the amplification of _____.

5. What would be the gain of a negative feedback amplifier with an internal gain A=100 and a feedback factor m=0.9?

6. Why is the control grid of a tube always held at negative potential W.R.T cathode.?

7. The relationship among bandwidth, resonant frequency and Q of a tuned circuit is _____.

8. The resonant circuit has ___________ impedance at the resonant frequency.

9. We have to match a 16-ohm speaker to an amplifier so that the effective load resistance is 10 KΩ. What should be the transformer turn ratio?

10. Which coupling does the final stage of a multistage amplifier use?

11. The output frequency of a half-wave rectifier is _____.

12. Which parameter is a measure of a vacuum tube's amplification capability?

13. The V-I characteristics of a triac in the first and third quadrants are essentially identical to those of _______ in the first quadrant

14. When a transistor has to act as a switch, it must operate in _____.

15. The required gain of an amplifier for sustained oscillation in the wein bridge oscillator is _____.

16. The Q-factor of a parallel tuned circuit is given by _____.

17. The output characteristics of an FET closely resemble the plate characteristics of a________ valve.

18. Which one of the following is a non-feedback type oscillator?

19. Tuned amplifiers are generally operated as

20. The most commonly used semiconductor in solid state devices is _____.

21. Which configuration of a transistor is preferred as an amplifier?

22. The overall gain of a multistage amplifier is 140. When negative feedback is applied, the gain is reduced to 17.5. The fraction of the output that is feedback to the input will be _____.

23. Which multivibrator is a square wave oscillator?

24. Which one of the following is Shockley's equation?

25. Two identical germanium diodes are connected in series opposition. A 10V battery is impressed upon this series arrangement. What will be the voltage across each diode room temperature if the Zener breakdown voltage of each diode is 9.8V?

26. The range of LC oscillators is _____.

27. Which device has the highest input impedance?

28. The maximum value of AC voltage appearing across the secondary of a transformer in a bridge circuit using a vacuum tube is 400 v. The peak inverse voltage of the diode should be _____.

29. Which condition must a transistor fulfill to act as an amplifier?

30. Tuning is generally accomplished by varying _____.

31. The slope of the D.C load line of a transistor circuit having a collector load Rc is _____.

32. The stability factor of a biasing circuit is 10. What does it mean?

33. If the A.C input to a half-wave rectifier has an R.M.S valve of 400/√2 v, the peak inverse voltage will be _____.

34. The ideal value of the stability factor is _____.

35. A 3-ohm load is coupled to a transistor amplifier through a step-down transformer. If the D.C resistance of the primary winding is 300Ω and the output resistance of the amplifier is 3KΩ, what should be the turn ratio for the transfer of maximum power?

36. The complementary MOS(CMOS) uses _____.

37. An :FET is a _____.

38. An FET has ________ temperature co-efficient of resistance.

39. The input and output voltages of a CE transistor amplifier are _____.

40. If in a transistor VCB= 4V , VBE = 0.7V, the VCE will be equal to _____.

41. Hartley oscillator is _____.

42. An SCR combines the features of_____.

43. A D.C milliammeter connected to a half-wave rectifier supplying a maximum current of 10mA will read _____.

44. A transistor amplifier has 4v,2mA as the operating point. For faithful amplification, the collector current due to signal alone should not exceed _____.

45. The impedance of a parallel tuned circuit at resonance is _____.

46. A reversed biased P-N junction has a resistance of the order of _____.

47. For an R-C phase shift oscillator , the frequency of oscillation will be given as _____.

48. For faithful amplification, VBE must not fall below _____.

49. If the input to a differentiating circuit is a square wave, the output will be _____.

50. In an R-C phase shift oscillator, an R-C network is designed to introduce a phase shift of _____ .

51. If in a transistor , Ic = 9.5mA , Ie = 10mA , the value of α will be _____.

52. If the input to an integrating circuit is a square wave, the output will be _____.

53. If the collector supply voltage is 10v, the collector cut off voltage under D.C conditions will be _____.

54. The maximum efficiency of a full wave rectifier is _____.

55. In the d.c. equivalent circuit of a transistor amplifier , the capacitors are regarded as _____.

56. An SCR is a solid state equivalent of a _____.

57. At parallel resonance, a tuned circuit offers an impedance of _____.

58. A three-stage amplifier has a first-stage voltage gain of 100, a second stage voltage gain of 200 and a third stage gain of 400. The total voltage gain in db will be _____.

59. In the enhancement mode (MOSFET) , conductivity increases _____.

60. In the collector feedback biasing, β = 57 , RC = 1 kΩ , IB = 60µA and VCB = 4.5V. The value of the stability factor will be _____.

61. Radio frequencies have their range above _____.

62. A varactor diode can function as a variable capacitor with a________ forward bias.

63. If a circuit of full-wave centre-tapped rectifier with capacitor filter employs a load RL = 100Ω, and C = 1050µF and the frequency is 50HZ , what would be the ripple factor?

64. A vacuum tube conducts current _____.

65. An A.C supply of 230v is applied to a half wave rectifier circuit through a transformer of turn ratio 10:1. Its D.C voltage output will be _____.

66. A triac can pass a portion of _____.

67. If in a transistor IE = 10.5mA , IC = 10mA,the value of β will be _____.

68. For good stabilization of the operating point in a voltage divider bias, the current I, flowing through potential dividers R1 and R2, should be equal to or greater than _____. (IB-base current)

69. An FET has the following parameters IDSS = 32mA , VGS ( off ) = -8V , VGS = -4.5V. What will be the drain current?

70. If the reverse bias on the gate of an FET is increased , the width of the conducting channel will _____.

71. According to the Barkhausen criterion for oscillators .....

72. A P-type material is _____.

73. Which particle generally carries the most momentum?

74. What causes particles to diffuse from regions of higher concentration to regions of lower concentration?

75. What is the name of the regime in which transistors pass current?

76. Which statement is true about the Zener Effect?

77. True or False? Pure Si has a low electrical resistivity at room temperature

78. What is the conventional unit of volume in semiconductor engineering?

79. In a plot of carrier concentration versus temperature, which of these is NOT a distinct region?

80. A space on a wafer between die is called a(n):

81. Which of these is a common method for producing single-crystal silicon?

82. What was the first transistor made of?

83. What happens to electrons to cause a semiconductor to gain electric conductivity?

84. Which semiconductor has a direct bandgap?

85. What is the bandgap of silicon?

86. What is the term for a semiconductor device manufacturing plant?

87. Which type of element is most widely used for the manufacture of semiconductor devices?

88. What is the value of kT at room temperature?

89. What are the four elements in CIGS?

90. What is the maximum theoretical efficiency for a single-junction silicon solar cell?

91. What devices are typically used to control volume in electronics?

92. On a circuit board what letter usually marks a transistor?

93. Memristors are also known as _________.

94. A degenerate semiconductor has which of the following characteristics?

95. In ellipsometry, the azimuth is the angle between the _______ and the plane of incidence.

96. What technique is commonly used to pattern semiconductors?

97. Which concept describes the chemical potential of a semiconductor?

98. The electron-volt is a unit of:

99. The wavelength of light emitted by an LED is determined by its:

100. What is an exciton?