Questions and answers for exam Preparation

MCQs

Total Questions : 117 | Page 11 of 12 pages

Question 101. The standardization of AC potentiometer is done by ____________

Using a DC standard source and d’ Arsonval galvanometer
Using AC standard sources and transfer instruments
Using a standard AC voltage source
Using a DC standard source and transfer instruments

Discuss Question

Answer: Option D. -> Using a DC standard source and transfer instruments
Answer: (d).Using a DC standard source and transfer instruments

Question 102. The inductance of a certain moving- iron ammeter is expressed as L = 10 + 3θ – \(\frac{θ^2}{4}\) μH, where θ is the deflection in radian from the zero position. The control spring torque is 25 × 10⁻⁶ Nm/rad. The meter carries a current of 5 A. What is the deflection?

Discuss Question

Answer: Option C. -> 1.2
Answer: (c).1.2

Question 103. A current of – 8 + 6\(\sqrt{2}\) (sin (ωt + 30°)) A is passed through three meters. The respective readings (in ampere) will be?

8, 6 and 10
8, 6 and 8
– 8, 10 and 10
-8, 2 and 2

Discuss Question

Answer: Option C. -> – 8, 10 and 10
Answer: (c).– 8, 10 and 10

Question 104. A rectifier type AC voltmeter consists of a series resistance R, an ideal full-wave rectifier bridge and a PMMC instrument. The internal resistance of the instrument is 100 Ω and a full- scale deflection is produced by a DC current of 1 mA. A voltage of 100 V (rms) is applied to the input terminals. The value of R required is?

63.56 Ω
89.83 Ω
89.83 kΩ
141.3 kΩ

Discuss Question

Answer: Option C. -> 89.83 kΩ
Answer: (c).89.83 kΩ

Question 105. A current of [2 + \(\sqrt{2}\) sin (314t + 30) + 2\(\sqrt{2}\) cos (952t +45)] is measured with a thermocouple type, 5A full scale, class 1 meter. The meter reading would lie in the range?

5 A ± 1 %
(2 + 3\(\sqrt{2}\)) A ± 1%
3 A ± 1.7 %
2 A ± 2.5 %

Discuss Question

Answer: Option C. -> 3 A ± 1.7 %
Answer: (c).3 A ± 1.7 %

Question 106. The discharge of a capacitor through a ballistic galvanometer produces a damped frequency of 0.125 Hz and successive swings of 120, 96 and 76.8 mm. The damping ratio is?

0.0568
0.0887
0.0357
0.0441

Discuss Question

Answer: Option C. -> 0.0357
Answer: (c).0.0357

Question 107. The discharge of a capacitor through a ballistic galvanometer produces a damped frequency of 0.125 Hz and successive swings of 120, 96 and 76.8 mm. The logarithmic decrement is?