NETWORK ANALYSIS AND SYNTHESIS QUESTION2

1. For amplifying, the frequency of the modulated signals, one may use

a. Class A amplifier

b. Class B amplifier

c. Class C amplifier

d. Class D amplifier

2. In a P-channel FET, the charge carriers are

a. Holes

b. Electrons

c. Both holes and electrons

d. Either holes or electrons

3. The darlington amplifier has

a. High current and voltage gain

b. High input resistance and current gain

c. Low input resistance and current gain

d. Low current and voltage gain

4. Identify the statement which is not applicable to series networks.

a. Same current flows through all parts of the circuit

b. Applied voltage equals the sum of different voltage drops

c. Powers are additive

d. Different resistors have same voltage drops

5. In a pure inductive circuit, the power absorbed is

a. Greater than unity

b. Less than unity

c. Infinity

d. Zero

6. Which theorem enables a number of voltage (for current) sources to be combined into a single voltage (or current) source?

a. Millmann’s theorem

b. Compensation theorem

c. Thevenin’s theorem

d. Superposition theorem

7. The power absorbed by resistor R is given by

a. P=V*V*I

b. P=I*R

c. P=V*I

d. P=I/R

8. A phono preamplifier provides ------------------ for the audio signal obtained from a moving coil cartridge.

a. Gain equalization

b. Amplitude equilazation

c. Phase equalization

d. All

9. In a 20ms, a sine wave goes through

a. 10 cycles

b. 10^2 cycles

c. 10^3 cycles

d. 10^4 cycles

10. The impedance for an RLC series circuit is given by

a. Z=R*R + (XL+Xc)^2

b. Z=sqrt(R*R) / (XL+Xc)^2

c. Z= sqrt(R*R) * (XL+Xc)^2

d. Z=sqrt(R*R) + (XL+Xc)^2

11. The superposition theorem and maximum power transfer theorem can be applied

a. Only to DC circuits

b. Only to AC circuits

c. To both AC & DC circuits

d. Either to DC r AC circuits

12. Higher value of quality factor

a. Decreases bandwidth

b. Increases bandwidth

c. No changeover bandwidth

d. None

13. Consider the two statements

I. Ohm’s law does not apply to non-linear devices involving step discontinuities

II. Ohm’s law in different forms can also be expressed as dv=Rdi

Among the following which one is correct?

a. Statement I

b. Statement II

c. Both I & II

d. Either I or II

14. The materials which exhibit paramagnetic properties are

a. Iron & copper

b. Aluminum & platinum

c. Silver 7 gold

d. Bismuth & tungsten

15. An oscillator converts ------------------- of any desired frequency.

a. DC to DC

b. AC to DC

c. AC to AC

d. DC to AC

16. Which is also termed as an ideal amplifier?

a. Class A amplifier

b. Class B amplifier

c. Class C amplifier

d. Class D amplifier

17. In a N-channel FET, the charge carriers are

a. Holes

b. Electrons

c. Both holes and electrons

d. Either holes or electrons

18. In an RC coupled amplifier, if the CE is disconnected the mid-band gain of the stage will

a. Increase

b. Decrease

c. Increase then decrease

d. Remain unaffected

19. In class A amplifier, the efficiency is --------------- and the distortion is -----------

a. Maximum, maximum

b. Maximum, minimum

c. Minimum, minimum

d. Minimum, maximum

20. Identify the statement which is not applicable to parallel circuits

a. Conductances are additive

b. Some voltage acts across all parts of the circuits

c. Powers are additive

d. Different resistors have same voltage drops

21. Power factor is

a. Sine of phase angle between voltage and current

b. Cosine of phase angle between voltage and current

c. Tangent of phase angle between voltage and current

d. Secant of phase angle between voltage and current

22. Which theorem postulates as follows “the summation of instantaneous power or complex power of sinusoidal sources in a network is zero”

a. Norton’s theorem

b. Maximum power transfer theorem

c. Tellegen’s theorem

d. Substitution theorem

23. Energy stored in an inductor is

a. L di/dt

b. Li di/dt

c. L (i^2/dt)

d. L dv/dt

24. If the real part of admittance is --------, then the imaginary part is ---------

a. Resistance, impedance

b. Impedance, Resistance

c. Conductance, Susceptance

d. Susceptance, Conductance

25. The phase angle for an RLC circuit is

a. Θ = sin

26. In a diode, the cut-in voltage and forward voltage drops are respectively

a. 0.7v, 0.7v

b. 0.7v, 1.0v

c. 0.7v, 0.6v

d. 1.0v, 0.7v

27. Maximum power transfer occurs at a

a. 100% efficiency

b. 50% efficiency

c. 75% efficiency

d. 25% efficiency

28. Which is called as tank circuit?

a. Series resonant circuit

b. Parallel resonant circuit

c. Both series and parallel resonant circuits

d. None

29. The farady’s law of electromagnetic induction is expressed as

a. N(dǾ/dt) V

b. -N(dv/dt)

c. N(dǾ/dt) V

d. N(dv/dt)

30. Curie point is

a. Temperature at which iron becomes red hot

b. Temperature at which iron loses magnetic property

c. Temperature above which iron retains its magnetic property

d. Temperature at which permeability becomes slightly excess to unity

31. The crystal oscillator frequency is very stable due to ----- of crystal

a. High V

b. High I

c. High G

d. High Q

32. Which amplifier can be used to amplify both AM and FM signals?

a. Class A amplifier

b. Class B amplifier

c. Class C amplifier

d. Class D amplifier

33. The gain band width product of atransistor is affected by

a. Transistor configuration

b. Operating collector current

c. Source impedance

d. Load in an amplifier circuit

34. The type of distortion allowable in audio amplifier is

a. Amplitude distortion

b. Frequency distortion

c. Phase distortion

d. Cross-over distortion

35. Kirchoff’s current law is applicable only to

a. Electric circuits

b. Electronic circuits

c. Closed loop in a network

d. Junctions in a network

36. The power factor is always

a. Less than unity

b. Greater than unity

c. Equal to unity

d. Equal to zero

37. Why does a lightning conductor have sharp points?

a. Charge density and electric field are relatively high at sharp points

b. Charge density and electric field are relatively low at sharp points

c. Charge density is low but electric field is high at sharp points

d. Charge density is high but electric field is low at sharp points

38. A pure inductor in general

a. Stores energy

b. Stores and dissipates energy

c. Dissipates but doesn’t store energy

d. Either stores or dissipates energy

39. Mesh analysis is applicable for

a. Plannar networks

b. Non-plannar networks

c. Both plannar and non-planner

d. Electronic networks

40. A network function is said to be stable when

a. The real parts of poles and zeros are negative

b. The real parts of poles and zeros are positive

c. The real parts of poles are positive and that of zeros are negative

d. The real parts of poles are negative and that of zeros are positive.

41. In a parallel RL circuit

a. The inductive current is real and lies on the j-axis

b. The inductive current is imaginary and lies on the j-axis

c. The inductive current is real and lies on the -j-axis

d. The inductive current is imaginary and lies on the -j-axis

42. The circuit is predominantly inductive only if

a. XL< Xc b. XL> Xc

c. XL= Xc

d. XL=0

43. A circuit is said to be in resonance only if the susceptance part or admittance is

a. Zero

b. Unity

c. Infinity

d. None

44. A conductor carrying current becomes hot after some time because of

a. Moving electrons colliding with other electrons as they pass through the molecules of atoms

b. Energy released by the electrons as they move along the conductor

c. Long distance traveled by the electrons

d. The type of material which it is made up of

45. Iron has a very good magnetic property, compared to other metals because

a. It is crystalline in structure

b. It is good conductor of electricity and heat

c. It is found in earth’s crust

d. Domains are subcrystalline in nature and has magnetic movement in same direction

46. Y cut quartz crystal has ---------- temperature coefficient.

a. Negative

b. Positive

c. Negative or positive

d. Zero

47. Ferrite cores commonly used at high frequency

a. Increase core losses

b. Decrease core losses

c. Increase induction

d. Increase resistance

48. Push-pull operation of device in amplifier minimizes

a. Even harmonic component

b. Odd harmonic component

c. Both even and odd harmonics

d. Either even or odd harmonic

49. The gain of an RC coupled amplifier

a. Falls at low frequency only

b. Falls at high frequency only

c. Falls at low and high frequencies

d. Remains constant at all frequencies

50. In transistorized class AB amplifier, the current

a. Flows for more than 180 but less than 360

b. Flows for less than 180

c. Flows for 180

d. Flows for 360

51. A higher ripple frequency signifies that

a. The output is closer to DC

b. The power supply is not good

c. The output has greater AC components

d. None

52. The current gain of a common base transistor circuit is

a. Very high

b. Moderate

c. Low

d. Nearly equal to unity

53. The clap oscillator is a modified form of

a. Phase shift oscillator

b. Wein bridge oscillator

c. Hartely oscillator

d. Colpitts oscillator

54. A Power supply with a DC output of 140v has a 50 Hz ripple of 1.4v. The percentage of ripple factor is given by

a. 2.4%

b. 1%

c. 0.14%

d. 0.1%

55. The advantage of using darlington pair circuit

a. Eliminates number of circuit components

b. Reduces bias voltage

c. Increases efficiency

d. Provides better stable output

56. The common mode rejection ratio of a BJT differential amplifier can be improved by

a. Increasing the emitter resistance

b. Increasing the collector resistance

c. Decreasing the emitter resistance

d. Decreasing the collector resistance

57. To generate 1 MHz signal output, the most suitable circuit is

a. Crystal oscillator

b. Phase shift oscillator

c. Hartley oscillator

d. Colpitts oscillator

58. Resonance frequency in an AC circuit is a phenomenon that occurs when

a. XL< Xc b. XL> Xc

c. XL= Xc

d. XL =1/ Xc

59. The process of introducing a DC level into an AC signal is known as

a. Positive clipping

b. Negative clipping

c. DC restoration

d. Biased parallel clipping

60. The decibel is a measurement of

a. Power

b. Voltage

c. Current

d. Power level

61. The common-collector (CC) amplifier has the highest

a. Voltage gain

b. Current gain

c. Power gain

d. Output impedance

62. Crossover distortion occurs in -------------- amplifiers

a. Class A

b. Class B

c. Class C

d. Class AB

63. Emitter follower is employed for

a. Current amplification

b. Voltage amplification

c. Power amplification

d. Impedance matching

64. An RC phase shift oscillator output will not produce an utput until the voltage gain of internal amplifier is

a. More than 19

b. More than 20

c. More than 39

d. More than 29

65. A negative feedback in an amplifier

a. Increases gain stability

b. Decreases distortion and noise level

c. Increases input impedance

d. All

66. Which of the following oscillators makes use of both positive and negative feedbacks?

a. Hartley oscillator

b. Colpitt’s oscillator

c. Phase shift oscillator

d. Wein bridge oscillator

67. In a common-emitter (CE) amplifier, which has the highest value?

a. Current gain

b. Output impedance

c. Input impedance

d. Power gain

68. The maximum overall efficiency of a class B push-pull amplifier cannot exceed

a. 50%

b. 78.5%

c. 85%

d. 96%

69. Which one is incorrect with respect to negative feedback amplifier?

a. Improve gain stability

b. Reduced distortion and noise

c. Improves frequency response

d. Increases output impedance

70. Bandwidth of a tuned circuit is given by

a. Q/F

b. F/Q

c. LF/CR

d. CR/F

71. Human ear can detect only

a. If the voltage gain of amplifier is 100

b. If the voltage gain of amplifier is above 70.7

c. If the voltage gain of amplifier falls below 70.7

d. If the voltage gain of amplifier is exactly at 70.7

72. Emitter follower is basically a

a. Common base amplifier

b. Common collector amplifier

c. Common emitter amplifier

d. Push-pull amplifier

73. The variation of amplifier gain with respect to frequency is mainly due to

a. Transformer coupling

b. Transistor characteristics

c. Miller effect

d. Stray capacitances

74. The emitter follower can also be employed as a buffer amplifier because of

a. High input impedance and low output impedances

b. High input impedance and high output impedances

c. Low input and low output impedances

d. Low input and high output impedances

75. The peak value of the input to a half-wave rectifier is 10v. The output peak value is

a. 8.50 V

b. 9.30 V

c. 10.2 V

d. 11.2 V

76. Load regulation is determined by

a. Changes in load current and input voltage

b. Changes in load current and output voltage

c. Changes in load resistance and input voltage

d. Changes in load current

77. If any of the diodes of the bridge full wave rectifier is found faulty(i.e. opens), then the rectifier output obtained is

a. 0 V

b. One-third of input voltage

c. Half wave rectified output voltage

d. Same input voltage

78. Emitter follower is similar to

a. Common base amplifier

b. Common collector amplifier

c. Common emitter amplifier

d. Push-pull amplifier

79. The process of introducing a DC level into an AC signal is known as

a. Positive clipping

b. Negative clipping

c. DC restoring

d. Biased parallel clipping

80. In the h-parameters of the transistor, the input resistance with output short-circuited and output conductance with input open-circuited is given by

a. h11 & h¬12

b. h21 & h¬22

c. h11 & h¬22

d. h12 & h¬21

81. Minimum requirement of a clipper circuit is

a. Diode

b. Resistor

c. Diode, Resistor, and capacitor

d. None

82. The ripple factor of a half wave rectifier is found to be

a. 1.57

b. 1.21

c. 1.12

d. 1.41

83. Minimum requirement of a clamper circuit is

a. Diode

b. Resistor

c. Diode, resistor, and capacitor

d. None

84. Without DC source, a clipper acts like

a. A clamper

b. A clipper

c. A rectifier

d. A chopper

85. The amplifier gain with positive feedback is given by

a. A/(1+βA)

b. A/(1-βA)

c. β/(1+A)

d. β/(1-A)

86. Which amplifier is most suitable for communication sound equipments?

a. Class C amplifier

b. Class B push-pull amplifier

c. Emitter follower

d. Class A amplifier

87. To have maximum bandwidth , the stray capacitance in the amplifier must be

a. Completely eliminated

b. Kept at maximum

c. Kept at minimum

d. None

88. Consider the following statements with respect to darlington pair

Statement 1: It has enormous impedance transformation capability

Statement 2: It provides very high β value

Which of the following is correct?

a. Statement 1 &2

b. Statement 1 but not 2

c. Statement 2 but not 1

d. Either statement 1 or 2

89. For an amplifier if the low frequency value is 1 for a frequency 6 MHz, then the gain bandwidth product is given by

a. 0.6 Hz

b. 6 KHz

c. 6 Hz

d. 6 MHz

90. The amplifier gain with positive feedback is given by

a. A/(1+βA)

b. A/(1-βA)

c. β/(1+A)

d. β/(1-A)

91. A series connected coupling and bypass capacitor in an amplifier cause a

a. Decrease in gain at low frequency

b. Increase in gain at high frequency

c. Decrease in gain at high frequency

d. Increase in gain at low frequency

92. In which amplifier the input and output signals are 180 out of phase to each other?

a. Common emitter amplifier

b. Common base amplifier

c. Common collector amplifier

d. Emitter follower

93. The crossover distortion seen in class B push-pull amplifier can be eliminated by

a. Locating the Q point of each transistor slightly above cut-off region

b. Locating the Q point of each transistor slightly below cut-off region

c. Locating the Q point of each transistor exactly at cut-off region

d. Locating the Q point of each transistor exactly at saturation region

94. In a circuit, if appreciable precision and stability of resistance is required, then one can prefer

a. Turret film type resistors]

b. Thin film resistors

c. Thick film resistors

d. Wire-wound resistors

95. A coil has an inductance of 1 Henry; a current changing at a rate of 2 amperes per second induces

a. 0 v

b. 1.2 v

c. 2 v

d. 4 v

96. A parallel resonant circuit has ------------- similar to resonant RLC circuit

a. Maximum impedance

b. Amplified current

c. Unity power factor

d. Minimum load resistance

97. The ampere size is a unit of

a. Power

b. Voltage

c. Current

d. Electric charge

98. The oscillations with efficient frequency stability and accuracy can be obtained from

a. Oscillator hartley

b. Colpitt’s oscillator

c. Crystal controlled oscillator

d. Phase shift oscillator

99. Which one of the following is responsible for harmonic distortion in an RC coupled amplifier?

a. Power source

b. Biasing resistor

c. Coupling capacitor

d. Transistor

100. In a parallelly connected circuit, the total resistance of the circuit decreases as the number of resistors connected parallelly

a. Decreases

b. Increases

c. Remains same

d. None