Quiznetik

Electronic Devices and Circuits | Set 2

1. What is the maximum collector efficiency of a transformer coupled class A power amplifier?

Correct : D. 50%

2. Class C amplifiers are used as

Correct : C. rf amplifiers

3. Find the voltage drop developed across a D’ Arsonval meter movement having an internal resistance of 1 kΩ and a full deflection current of 150uA.

Correct : B. 150 mv

4. If the capacitor from emitter to ground in a common emitter amplifier is removed, the voltage gain

Correct : B. decreases

5. Comparatively, power amplifier has β.

Correct : C. small

6. The driver stage usually employs amplifier.

Correct : A. class a power

7. The push-pull circuit must use operation.

Correct : B. class b

8. A complementary-symmetry amplifier has

Correct : A. one pnp and one npn transistor

9. Power amplifiers generally use transformer coupling because transformer coupling provides

Correct : C. impedance matching

10. The output transformer used in a power amplifier is a/an                 transformer

Correct : B. step-down

11. An emitter follower has a voltage gain that is

Correct : B. approximately equal to one

12. The input impedance of the base of an emitter follower is usually

Correct : B. high

13. The ac base voltage of an emitter follower is across the

Correct : D. emitter diode and external ac emitter resistance

14. The output voltage of an emitter follower is across the

Correct : C. load resistor

15. The differential amplifier has

Correct : C. two inputs and one output

16. The differential amplifier produces outputs that are

Correct : D. the difference of the two input voltages

17. Which factor does not affect CMOS loading?

Correct : C. output capacitance of the load gates

18. Which transistor element is used in CMOS logic?

Correct : B. mosfet

19. A Darlington pair is used for

Correct : D. high current gain

20. What is the effect of cascading amplifier stages?

Correct : B. increase in the voltage gain and reduction in the bandwidth

21. An open-drain gate is the CMOS counterpart of .

Correct : A. an open-collector ttl gate

22. The decibel gain of a cascaded amplifier equals to

Correct : B. sum of individual gains

23. The most desirable feature of transformer coupling is its

Correct : C. ability to provide impedance matching between stages

24. A transformer coupled amplifier would give

Correct : B. impedance matching

25. One of the advantages of a Darlington pair is that it has enormous                          transformation capacity.

Correct : C. impedance

26. Bootstrapping is used in emitter follower configurations to

Correct : D. increase the input resistance

27. To determine the polarity of the voltage drop across a resistor, it is necessary to know

Correct : B. direction of current through the resistor

28. "Maximum power output is obtained from a network when the load resistance is equal to the output resistance of the network as seen from the terminals of the load". The above statement is associated with

Correct : D. maximum power transfer theorem

29. "In any linear bilateral network, if a source of e.m.f. E in any branch produces a current I in any other branch, then same e.m.f. acting in the second branch would produce the same current / in the first branch". The above statement is associated with

Correct : C. reciprocity theorem

30. Which of the following is non-linear circuit parameter?

Correct : A. inductance

31. A capacitor is generally a

Correct : C. linear and bilateral

32. "In any network containing more than one sources of e.m.f. the current in any branch is the algebraic sum of a number of individual fictitious currents (the number being equal to the number of sources of e.m.f.), each of which is due to separate action of each source of e.m.f., taken in order, when the remaining sources of e.m.f. are replaced by conductors, the resistances of which are equal to the internal resistances of the respective sources". The above statement is associated with

Correct : C. superposition theorem

33. Kirchhoff s law is applicable to

Correct : D. both a.c. as well d.c. circuits

34. Kirchhoff s law is not applicable to circuits with

Correct : C. distributed parameters

35. The resistance LM will be

Correct : A. 6.66 q

36. For high efficiency of transfer of power, internal resistance of the source should be

Correct : B. less than the load resistance

37. Efficiency of power transfer when maximum transfer of power c

Correct : D. 50%

38. If resistance across LM in Fig. 2.30 is 15 ohms, the value of R is

Correct : C. 30 q

39. For maximum transfer of power, internal resistance of the source should be

Correct : A. equal to load resistance

40. If the energy is supplied from a source, whose resistance is 1 ohm, to a load of 100 ohms the source will be

Correct : A. a voltage source

41. The circuit whose properties are same in either direction is known as

Correct : B. bilateral circuit

42. In a series parallel circuit, any two resistances in the same current path must be in

Correct : A. series with each other

43. The circuit has resistors, capacitors and semi-conductor diodes. The circuit will be known as

Correct : A. non-linear circuit

44. A non-linear network does not satisfy

Correct : C. both homogeneity as well as superposition condition

45. An ideal voltage source has

Correct : A. zero internal resistance

46. A network which contains one or more than one source of e.m.f. is known as

Correct : C. passive network

47. The superposition theorem is applicable to

Correct : C. linear responses only

48. Application of Norton's theorem to a circuit yields

Correct : A. equivalent current source and impedance in series

49. Mill man’s theorem yields

Correct : D. equivalent voltage or current source

50. The superposition theorem is applicable to

Correct : D. current voltage and power

51. Between the branch voltages of a loop the Kirchhoff s voltage law imposes

Correct : B. linear constraints

52. A terminal where three on more branches meet is known as

Correct : A. node

53. Which of the following is the passive element ?

Correct : A. capacitance

54. Which of the following is a bilateral element ?

Correct : C. capacitance

55. A closed path made by several branches of the network is known as

Correct : B. loop

56. A linear resistor having 0 < R < °o is a

Correct : C. both current controlled and voltage controlled resistor

57. A star circuit has element of resistance R/2. The equivalent delta elements will be

Correct : B. fi?

58. A delta circuit has each element of value R/2. The equivalent elements of star circuit with be

Correct : A. rig

59. While calculating Rth in Thevenin's theorem and Norton equivalent

Correct : A. all independent sources are made dead

60. The number of independent equations to solve a network is equal to

Correct : A. the number of chords

61. The superposition theorem requires as many circuits to be solved as there are

Correct : C. sources

62. Which of the following is a concern when using CMOS type devices?

Correct : B. electrostatic discharge

63. Which of the following is not a solution to interface problems between CMOS and TTL?

Correct : B. pull-down resistor

64. Which of the following is not a common logic family used today?

Correct : A. rtl

65. The output current for a LOW output is called a(n)

Correct : B. sink current.

66. A family of logic devices designed for extremely high speed applications is called

Correct : B. ecl.

67. Unused inputs on TTL, AND, and NAND gates

Correct : D. all of the above are correct.

68. The lower transistor of a totem-pole output is OFF when the gate output is

Correct : A. high.

69. The input transistor on a TTL circuit is unusual in that it has

Correct : D. multiple emitters.

70. The difference between VOH and VIH voltages is known as

Correct : B. noise margin.

71. The upper transistor of a totem-pole output is OFF when the gate output is

Correct : D. low.

72. The major advantage of TTL logic circuits over CMOS is

Correct : A. lower propagation delay.

73. The maximum current for a HIGH output on a standard TTL gate is

Correct : B. -400 µa.

74. The maximum current for a LOW output on a standard TTL gate is

Correct : D. 16 ma.

75. The major advantage of CMOS logic circuits over TTL is

Correct : A. very low power consumption.

76. The abbreviated designation for input current with a LOW input is

Correct : C. iil.

77. Fan-out for a typical TTL gate is .

Correct : A. 10

78. In order to interface an FPGA with an external device, you must set the value of the

Correct : D. all of the above

79. The abbreviated designator for a LOW output voltage is

Correct : C. vol.

80. The lower transistor of a totem-pole output is saturated when the gate output is

Correct : B. low.

81. Typical TTL HIGH level output voltage is

Correct : C. 3.4 v.

82. The standard 74XX TTL IC family was originally developed in the

Correct : B. 1960s.

83. The minimum output voltage recognized as a HIGH by a TTL gate is

Correct : B. 2.4 v.

84. An open-collector TTL gate

Correct : A. can sink current but cannot source current.

85. The minimum input voltage recognized as a HIGH by a TTL gate is

Correct : C. 2.0 v.

86. Which of the following digital IC logic families is most susceptible to static discharge?

Correct : C. mos

87. Each input on a TTL gate is connected to the transistor's

Correct : D. emitter

88. The time it takes for an input signal to pass through internal circuitry and generate the appropriate output effect is known as

Correct : A. propagation delay

89. In a common emitter, unbypassed resister provides

Correct : A. voltage shunt feedback

90. Negative feedback in an amplifier

Correct : A. reduces gain

91. An amplifier without feedback has a voltage gain of 50, input resistance is 1 KΩ & Output resistance of 2.5KΩ.The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 is

Correct : B. 1/5kΩ

92. The fan out of a MOS logic gate is higher than that of TTL gates because of its

Correct : D. high input impedance

93. Transformer coupling can be used in amplifiers

Correct : C. either power or voltage

94. When negative current feedback is applied to an amplifier, its output impedance

Correct : A. increases

95. The quiescent current of a FET amplifier is

Correct : C. id

96. The total decibel voltage gain of two cascaded voltage amplifier where individual voltage gains are 10 and 100 is

Correct : B. 60

97. The frequency response of the combined amplifier can be compared with

Correct : D. an and gate

98. Minimum interference with frequency response can be given by

Correct : A. direct coupling

99. The impedance of a load must match the impedance of the amplifier so that

Correct : D. maximum power is transferred to the load

100. The ratio output rms power in watts to the input dc power in watts in the different amplifier class is called .

Correct : C. efficiency