Shunt Motors Speed MCQ Questions & Answers

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

Question 1

A 16-pole, 3-phase, 60 Hz induction motor is operating at a speed of 150 rpm. The frequency of the rotor current of the motor in Hz is __________

A. 20

B. 40

C. 30

D. 10

Question 2

A 3-phase induction machine draws active power P and reactive power Q from the grid. If it is operated as a generator, then P and Q will be _________

A. Positive and Negative

B. Negative and Positive

C. Positive and Positive

D. Negative and Negative

Question 3

Calculate mark to space ratio if the system is on for 26.3 sec and off for 24.2 sec.

A. 1.086

B. 1.042

C. 1.214

D. 1.876

Question 4

Calculate the active power in a .154 H inductor.

A. 22 W

B. 14 W

C. 45 W

D. 0 W

Question 5

Calculate the amplitude of the sinusoidal waveform z(t)=715sin(165?t+2?÷468).

A. 710

B. 715

C. 716

D. 718

Question 6

Calculate the time period of the waveform z(t)=24sin(?t+?÷4)+4sin(2?t+?÷6).

A. 2 sec

B. 3 sec

C. 4 sec

D. 1 sec

Question 7

Calculate the total heat dissipated in a resistor of 50 ? when 1.4 A current flows through it.

A. 98 W

B. 92 W

C. 91 W

D. 93 W

Question 8

If induction motor air gap power is 10 KW and mechanically developed power is 8 KW, then rotor ohmic loss will be _________ KW.

A. 1

B. 2

C. 3

D. 4

Question 9

If induction motor air gap power is 48 KW and gross developed power is 28 KW, then rotor ohmic loss will be _________ KW.

A. 10

B. 20

C. 30

D. 40

Question 10

The advantage of the double squirrel cage induction motor over a single cage rotor is that its _______

A. Efficiency is higher

B. Power factor is higher

C. Slip is larger

D. Starting current is lower

Question 11

The power factor of a squirrel cage induction motor is ___________

A. Low at light load only

B. Low at heavy loads only

C. Low at the light and heavy loads both

D. Low at rate load only

Question 12

The short circuit test on a 3-? induction motor is conducted at a rotor speed of _______

A. Zero

B. < Ns

C. > Ns

D. Ns

Question 13

The slope of the V-I curve is 39.1°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

A. .81 ?

B. .36 ?

C. .75 ?

D. .84 ?

Question 14

Calculate the amplitude of the sinusoidal waveform z(t)=715sin(165πt+2π÷468).

A. 710

B. 715

C. 716

D. 718

Question 15

Calculate the time period of the waveform z(t)=24sin(πt+π÷4)+4sin(2πt+π÷6).

A. 2 sec

B. 3 sec

C. 4 sec

D. 1 sec

Question 16

Calculate the total heat dissipated in a resistor of 50 Ω when 1.4 A current flows through it.

A. 98 W

B. 92 W

C. 91 W

D. 93 W

Question 17

The short circuit test on a 3-φ induction motor is conducted at a rotor speed of _______

A. Zero

B. < Ns

C. > Ns

D. Ns

Question 18

The slope of the V-I curve is 39.1°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

A. .81 Ω

B. .36 Ω

C. .75 Ω

D. .84 Ω