set-2

51. In a series R-L-C circuit, the voltage across the inductor and capacitor are ______ at resonance.

1. Equal and opposite

2. Equal and in phase

3. Unequal and opposite

4. Unequal and in phase

Show me the answer

Answer: 1. Equal and opposite

Explanation:

• At resonance, the voltage across the inductor ($V_L$) and the capacitor ($V_C$) are equal in magnitude but opposite in phase.

• Therefore, they cancel each other out, and the total voltage across the LC combination is zero.

• The correct answer is Equal and opposite.

52. In a series R-L-C circuit, the power factor at resonance is ______.

1. Unity

2. Zero

3. Lagging

4. Leading

Show me the answer

Answer: 1. Unity

Explanation:

• At resonance, the impedance of the series R-L-C circuit is purely resistive ($Z = R$).

• The phase angle between voltage and current is zero, and the power factor is unity.

• Therefore, the correct answer is Unity.

53. In a series R-L-C circuit, the impedance at resonance is ______.

1. Minimum

2. Maximum

3. Zero

4. Infinite

Show me the answer

Answer: 1. Minimum

Explanation:

• At resonance, the impedance of the series R-L-C circuit is minimum and equal to the resistance ($Z = R$).

• Therefore, the correct answer is Minimum.

54. In a series R-L-C circuit, the bandwidth is ______.

1. Directly proportional to Q factor

2. Inversely proportional to Q factor

3. Directly proportional to resonant frequency

4. Inversely proportional to resonant frequency

Show me the answer

Answer: 2. Inversely proportional to Q factor

Explanation:

• The bandwidth ($BW$) of a series R-L-C circuit is given by: $BW = \frac{f_r}{Q}$ where:

  • $f_r$ = resonant frequency,

  • $Q$ = quality factor.

• Therefore, the bandwidth is inversely proportional to the Q factor.

• The correct answer is Inversely proportional to Q factor.

55. In a series R-L-C circuit, the quality factor is ______.

1. Directly proportional to resonant frequency

2. Inversely proportional to resonant frequency

3. Directly proportional to bandwidth

4. Inversely proportional to bandwidth

Show me the answer

Answer: 1. Directly proportional to resonant frequency

Explanation:

• The quality factor ($Q$) of a series R-L-C circuit is given by: $Q = \frac{f_r}{BW}$ where:

  • $f_r$ = resonant frequency,

  • $BW$ = bandwidth.

• Therefore, the quality factor is directly proportional to the resonant frequency.

• The correct answer is Directly proportional to resonant frequency.

56. In a series R-L-C circuit, the resonant frequency is ______.

1. $\frac{1}{2\pi \sqrt{LC}}$

2. $\frac{1}{2\pi \sqrt{RC}}$

3. $\frac{1}{2\pi \sqrt{RL}}$

4. $\frac{1}{2\pi \sqrt{RLC}}$

Show me the answer

Answer: 1. $\frac{1}{2\pi \sqrt{LC}}$

Explanation:

• The resonant frequency ($f_r$) of a series R-L-C circuit is given by: $f_r = \frac{1}{2\pi \sqrt{LC}}$

• Therefore, the correct answer is $\frac{1}{2\pi \sqrt{LC}}$.

57. In a parallel R-L-C circuit, the current at resonance is ______.

1. Minimum

2. Maximum

3. Zero

4. Infinite

Show me the answer

Answer: 1. Minimum

Explanation:

• At resonance, the impedance of the parallel R-L-C circuit is maximum, and the current is minimum.

• Therefore, the correct answer is Minimum.

58. In a parallel R-L-C circuit, the impedance at resonance is ______.

1. Minimum

2. Maximum

3. Zero

4. Infinite

Show me the answer

Answer: 2. Maximum

Explanation:

• At resonance, the impedance of the parallel R-L-C circuit is maximum.

• Therefore, the correct answer is Maximum.

59. In a parallel R-L-C circuit, the power factor at resonance is ______.

1. Unity

2. Zero

3. Lagging

4. Leading

Show me the answer

Answer: 1. Unity

Explanation:

• At resonance, the impedance of the parallel R-L-C circuit is purely resistive ($Z = R$).

• The phase angle between voltage and current is zero, and the power factor is unity.

• Therefore, the correct answer is Unity.

60. In a parallel R-L-C circuit, the bandwidth is ______.

1. Directly proportional to Q factor

2. Inversely proportional to Q factor

3. Directly proportional to resonant frequency

4. Inversely proportional to resonant frequency

Show me the answer

Answer: 2. Inversely proportional to Q factor

Explanation:

• The bandwidth ($BW$) of a parallel R-L-C circuit is given by: $BW = \frac{f_r}{Q}$ where:

  • $f_r$ = resonant frequency,

  • $Q$ = quality factor.

• Therefore, the bandwidth is inversely proportional to the Q factor.

• The correct answer is Inversely proportional to Q factor.

61. In a parallel R-L-C circuit, the quality factor is ______.

1. Directly proportional to resonant frequency

2. Inversely proportional to resonant frequency

3. Directly proportional to bandwidth

4. Inversely proportional to bandwidth

Show me the answer

Answer: 1. Directly proportional to resonant frequency

Explanation:

• The quality factor ($Q$) of a parallel R-L-C circuit is given by: $Q = \frac{f_r}{BW}$ where:

  • $f_r$ = resonant frequency,

  • $BW$ = bandwidth.

• Therefore, the quality factor is directly proportional to the resonant frequency.

• The correct answer is Directly proportional to resonant frequency.

62. In a parallel R-L-C circuit, the resonant frequency is ______.

1. $\frac{1}{2\pi \sqrt{LC}}$

2. $\frac{1}{2\pi \sqrt{RC}}$

3. $\frac{1}{2\pi \sqrt{RL}}$

4. $\frac{1}{2\pi \sqrt{RLC}}$

Show me the answer

Answer: 1. $\frac{1}{2\pi \sqrt{LC}}$

Explanation:

• The resonant frequency ($f_r$) of a parallel R-L-C circuit is given by: $f_r = \frac{1}{2\pi \sqrt{LC}}$

• Therefore, the correct answer is $\frac{1}{2\pi \sqrt{LC}}$.

63. In a series R-L-C circuit, the voltage across the resistor at resonance is ______.

1. Equal to the applied voltage

2. Zero

3. Maximum

4. Minimum

Show me the answer

Answer: 1. Equal to the applied voltage

Explanation:

• At resonance, the voltage across the inductor ($V_L$) and the capacitor ($V_C$) cancel each other out.

• The entire applied voltage appears across the resistor ($V_R$).

• Therefore, the correct answer is Equal to the applied voltage.

64. In a parallel R-L-C circuit, the current through the resistor at resonance is ______.

1. Equal to the total current

2. Zero

3. Maximum

4. Minimum

Show me the answer

Answer: 1. Equal to the total current

Explanation:

• At resonance, the current through the inductor ($I_L$) and the capacitor ($I_C$) cancel each other out.

• The entire current flows through the resistor ($I_R$).

• Therefore, the correct answer is Equal to the total current.

65. In a series R-L-C circuit, the voltage across the inductor at resonance is ______.

1. Q times the applied voltage

2. Zero

3. Maximum

4. Minimum

Show me the answer

Answer: 1. Q times the applied voltage

Explanation:

• At resonance, the voltage across the inductor ($V_L$) is given by: $V_L = Q \cdot V$ where:

  • $Q$ = quality factor,

  • $V$ = applied voltage.

• Therefore, the correct answer is Q times the applied voltage.

66. In a parallel R-L-C circuit, the current through the inductor at resonance is ______.

1. Q times the total current

2. Zero

3. Maximum

4. Minimum

Show me the answer

Answer: 1. Q times the total current

Explanation:

• At resonance, the current through the inductor ($I_L$) is given by: $I_L = Q \cdot I$ where:

  • $Q$ = quality factor,

  • $I$ = total current.

• Therefore, the correct answer is Q times the total current.

67. In a series R-L-C circuit, the voltage across the capacitor at resonance is ______.

1. Q times the applied voltage

2. Zero

3. Maximum

4. Minimum

Show me the answer

Answer: 1. Q times the applied voltage

Explanation:

• At resonance, the voltage across the capacitor ($V_C$) is given by: $V_C = Q \cdot V$ where:

  • $Q$ = quality factor,

  • $V$ = applied voltage.

• Therefore, the correct answer is Q times the applied voltage.

68. In a parallel R-L-C circuit, the current through the capacitor at resonance is ______.

1. Q times the total current

2. Zero

3. Maximum

4. Minimum

Show me the answer

Answer: 1. Q times the total current

Explanation:

• At resonance, the current through the capacitor ($I_C$) is given by: $I_C = Q \cdot I$ where:

  • $Q$ = quality factor,

  • $I$ = total current.

• Therefore, the correct answer is Q times the total current.

69. In a series R-L-C circuit, the power dissipated at resonance is ______.

1. Maximum

2. Minimum

3. Zero

4. Infinite

Show me the answer

Answer: 1. Maximum

Explanation:

• At resonance, the impedance of the series R-L-C circuit is minimum, and the current is maximum.

• Therefore, the power dissipated is maximum.

• The correct answer is Maximum.

70. In a parallel R-L-C circuit, the power dissipated at resonance is ______.

1. Minimum

2. Maximum

3. Zero

4. Infinite

Show me the answer

Answer: 1. Minimum

Explanation:

• At resonance, the impedance of the parallel R-L-C circuit is maximum, and the current is minimum.

• Therefore, the power dissipated is minimum.

• The correct answer is Minimum.

71. In a series R-L-C circuit, the current lags the voltage when ______.

1. $X_L > X_C$

2. $X_C > X_L$

3. $R > X_L$

4. $R > X_C$

Show me the answer

Answer: 1. $X_L > X_C$

Explanation:

• In a series R-L-C circuit, the current lags the voltage when the inductive reactance ($X_L$) is greater than the capacitive reactance ($X_C$).

• Therefore, the correct answer is $X_L > X_C$.

72. In case of Short Circuit, ______ current will flow in the Circuit.

1. Zero

2. Very Low

3. Normal

4. Infinite

Show me the answer

Answer: 4. Infinite

Explanation:

• In a short circuit, the resistance is effectively zero, and the current becomes extremely high (theoretically infinite).

• Therefore, the correct answer is Infinite.

73. Ω (Ohm) is the Unit of ______?

1. Resistance (R)

2. Inductive Reactance ($X_L$)

3. Capacitive Reactance ($X_C$)

4. All of the above

Show me the answer

Answer: 4. All of the above

Explanation:

• The unit ohm (Ω) is used for:

  • Resistance ($R$),

  • Inductive reactance ($X_L$),

  • Capacitive reactance ($X_C$).

• Therefore, the correct answer is All of the above.

74. Siemens or Mho (G) is the unit of ______?

1. Conductance

2. Admittance

3. Both A & B

4. None of the above

Show me the answer

Answer: 3. Both A & B

Explanation:

• The unit siemens (S) or mho (℧) is used for:

  • Conductance ($G = \frac{1}{R}$),

  • Admittance ($Y = \frac{1}{Z}$).

• Therefore, the correct answer is Both A & B.

75. Which of the following elements of electrical engineering cannot be analyzed using Ohm’s law?

1. Capacitors

2. Inductors

3. Transistors

4. Resistance

Show me the answer

Answer: 3. Transistors

Explanation:

• Ohm’s law is applicable only to linear elements like resistors, capacitors, and inductors.

• Transistors are non-linear devices and cannot be analyzed using Ohm’s law.

• Therefore, the correct answer is Transistors.

76. Which of the following is a correct representation of peak value in an AC Circuit?

1. RMS value / Peak factor

2. RMS value * Form factor

3. RMS value / Form factor

4. RMS value * Peak factor

Show me the answer

Answer: 4. RMS value * Peak factor

Explanation:

• The peak value of an AC waveform is given by: $V_{peak} = V_{rms} \times \text{Peak factor}$ where the peak factor for a sinusoidal waveform is $\sqrt{2}$.

• Therefore, the correct answer is RMS value * Peak factor.

77. How many cycles will an AC signal make in 2 seconds if its frequency is 100 Hz?

1. 50

2. 100

3. 150

4. 200

Show me the answer

Answer: 4. 200

Explanation:

• The number of cycles in a given time is calculated as: $\text{Number of cycles} = \text{Frequency} \times \text{Time}$ $\text{Number of cycles} = 100 \, \text{Hz} \times 2 \, \text{s} = 200$

• Therefore, the correct answer is 200.

78. What kind of quantity is an Electric potential?

1. Vector quantity

2. Tensor quantity

3. Scalar quantity

4. Dimensionless quantity

Show me the answer

Answer: 3. Scalar quantity

Explanation:

• Electric potential is a scalar quantity because it has only magnitude and no direction.

• Therefore, the correct answer is Scalar quantity.

79. Which of the following is a correct representation of average value in an AC Circuit?

1. RMS value / Form factor

2. RMS value * Form factor

3. RMS value / Peak factor

4. RMS value * Peak factor

Show me the answer

Answer: 1. RMS value / Form factor

Explanation:

• The average value of an AC waveform is given by: $V_{avg} = \frac{V_{rms}}{\text{Form factor}}$ where the form factor for a sinusoidal waveform is approximately 1.11.

• Therefore, the correct answer is RMS value / Form factor.