Explore topic-wise MCQs in Electrical Machines.

This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Machines knowledge and support exam preparation. Choose a topic below to get started.

1.

The velocity of the dc machine at the final state is ________

A. E/Bl
B. Bl/E
C. EBl
D. None of the mentioned
Answer» B. Bl/E
Discussion
2.

The variation of current in the armature can be best expressed by which of the below curves?

A. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q13a.png"><img alt="The variation of current in the armature - option a" class="alignnone size-full wp-image-160795" height="300" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q13a.png" width="164"/></a>
B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q13b.png"><img alt="The variation of current in the armature - option b" class="alignnone size-full wp-image-160796" height="300" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q13b.png" width="183"/></a>
C. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q13c.png"><img alt="The variation of current in the armature - option c" class="alignnone size-full wp-image-160797" height="300" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q13c.png" width="248"/></a>
D. An impulse signal
Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q13b.png"><img alt="The variation of current in the armature - option b" class="alignnone size-full wp-image-160796" height="300" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q13b.png" width="183"/></a>
Discussion
3.

Pulsating torque frequency in universal motor is ________

A. 2f
B. f
C. f/2
D. 4f
Answer» B. f
Discussion
4.

For a universal motor, the rated supply current is 10A giving a rated torque of 100 N-m. If a current of 5A is applied, what will be generated torque vary to?

A. 250 N-m
B. 400 N-m
C. 500 N-m
D. 1000 N-m
Answer» C. 500 N-m
Discussion
5.

DC Motor torque depends on ________

A. geometry
B. magnetic properties
C. any of the mentioned
D. both geometry and magnetic properties of the structure
Answer» E.
Discussion
6.

The cogging torque is absent in the permanent magnet dc machine is due to ________

A. non-magnetic nature of rotor
B. magnetic nature of rotor
C. absence of ac supply
D. any of the mentioned
Answer» B. magnetic nature of rotor
Discussion
7.

If the torque is in the direction of rotation, the DC machine acts as ________

A. generator
B. motor
C. amplidyne
D. any of the mentioned
Answer» B. motor
Discussion
8.

If the torque induced is zero in the dc machine, it can be said that ____________

A. current is zero
B. flux can be zero
C. current or flux=0
D. any of the mentioned
Answer» B. flux can be zero
Discussion
9.

The torque induced beyond the pole shoes in the DC machine is?

A. 0
B. 2/pi *phi *i
C. 4/pi *phi *i
D. none of the mentioned
Answer» B. 2/pi *phi *i
Discussion
10.

Choose the correct representation, which depict a non-zero torque in the armature?

A. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q1a.png"><img alt="The non-zero torque in the armature - option a" class="alignnone size-full wp-image-160792" height="91" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q1a.png" width="300"/></a>
B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q1b.png"><img alt="The non-zero torque in the armature - option b" class="alignnone size-full wp-image-160793" height="99" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q1b.png" width="300"/></a>
C. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q1c.png"><img alt="The non-zero torque in the armature - option c" class="alignnone size-full wp-image-160794" height="114" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q1c.png" width="300"/></a>
D. any of the mentioned
Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q1b.png"><img alt="The non-zero torque in the armature - option b" class="alignnone size-full wp-image-160793" height="99" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-dc-machine-torque-q1b.png" width="300"/></a>
Discussion