# Power Supply Effect MCQ Questions & Answers

Power Supply Effect MCQs : This section focuses on the "Power Supply Effect". These Multiple Choice Questions (MCQs) should be practiced to improve the Power Supply Effect skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.

Question 1

A 2-pole lap wound generator with 44 armature conductors and a flux per pole of .07 Wb has an armature current of 80 A. The developed torque is _________

A. 39.7 N-m
B. 39.2 N-m
C. 38.4 N-m
D. 37.2 N-m

Question 2

A 2-pole, 3-phase, 50 Hz induction motor is operating at a speed of 400 rpm. The frequency of the rotor current of the motor in Hz is __________

A. 43.33
B. 42.54
C. 43.11
D. 41.47

Question 3

A 3-phase induction motor runs at almost 1100 rpm at no load and 640 rpm at full load when supplied with power from a 50 Hz, 3-phase supply. What is the corresponding speed of the rotor field with respect to the rotor?

A. 430 revolution per minute
B. 440 revolution per minute
C. 460 revolution per minute
D. 450 revolution per minute

Question 4

Calculate the active power in a 1 ? resistor with 2 A current flowing through it.

A. 2 W
B. 4 W
C. 7 W
D. 1 W

Question 5

Calculate the moment of inertia of the disc having a mass of 1 kg and radius of 1 m.

A. 1 kgm2
B. .5 kgm2
C. 2 kgm2
D. 3 kgm2

Question 6

Calculate the moment of inertia of the thin spherical shell having a mass of 3 kg and diameter of 6 cm.

A. .0178 kgm2
B. .0147 kgm2
C. .0398 kgm2
D. .0144 kgm2

Question 7

Calculate the phase angle of the sinusoidal waveform w(t)=.45sin(87?t+8?÷787).

A. 2?÷39
B. 8?÷787
C. 5?÷74
D. 42?÷4

Question 8

The ferrite cores are used for ____________ transformers.

A. Small transformers
B. Medium transformers
C. Large transformers
D. Medium and small transformers

Question 9

The frame of a synchronous motor is made of _________

A. Aluminum
B. Silicon steel
C. Cast iron
D. Stainless steel

Question 10

The slope of the V-I curve is 13°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

A. .2544 ?
B. .7771 ?
C. .2308 ?
D. .5788 ?

Question 11

The slope of the V-I curve is 45°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

A. 2 ?
B. 3 ?
C. 4 ?
D. 1 ?

Question 12

Which of the following core has linear characteristics?

A. Air core
B. Steel core
C. CRGO core
D. Iron core

Question 13

Which one of the following methods would give a higher than the actual value of regulation of the alternator.

A. ZPF method
B. MMF method
C. EMF method
D. ASA method

Question 14

Calculate the active power in a 1 Ω resistor with 2 A current flowing through it.

A. 2 W
B. 4 W
C. 7 W
D. 1 W

Question 15

Calculate the phase angle of the sinusoidal waveform w(t)=.45sin(87πt+8π÷787).

A. 2π÷39
B. 8π÷787
C. 5π÷74
D. 42π÷4

Question 16

The slope of the V-I curve is 13°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

A. .2544 Ω
B. .7771 Ω
C. .2308 Ω
D. .5788 Ω

Question 17

The slope of the V-I curve is 45°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

A. 2 Ω
B. 3 Ω
C. 4 Ω
D. 1 Ω