Explore topic-wise MCQs in Electrical Machines.

This section includes 12 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.

Circle diagram for the variable rotor resistance and fixed reactance is most appropriately shown by

A. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q16a.png"><img alt="Circle diagram for the variable rotor resistance &amp; fixed reactance - option a" class="alignnone size-full wp-image-161123" height="300" sizes="(max-width: 268px) 100vw, 268px" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q16a.png" srcset="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q16a.png 268w, https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q16a-200x225.png 200w" width="268"/></a>
B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15d.png"><img alt="Circle diagram for the variable rotor resistance &amp; fixed reactance - option b" class="alignnone size-full wp-image-161121" height="158" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15d.png" width="300"/></a>
C. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15c.png"><img alt="Circle diagram for the variable rotor resistance &amp; fixed reactance - option c" class="alignnone size-full wp-image-161120" height="300" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15c.png" width="158"/></a>
D. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15a.png"><img alt="Circle diagram for the variable rotor resistance &amp; fixed reactance - option d" class="alignnone size-full wp-image-161118" height="108" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15a.png" width="300"/></a>
Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15d.png"><img alt="Circle diagram for the variable rotor resistance &amp; fixed reactance - option b" class="alignnone size-full wp-image-161121" height="158" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15d.png" width="300"/></a>
Discussion
2.

Circle diagram for the fixed rotor resistance and variable reactance is most appropriately shown by?

A. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15a.png"><img alt="Circle diagram for the fixed rotor resistance &amp; variable reactance - option a" class="alignnone size-full wp-image-161118" height="108" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15a.png" width="300"/></a>
B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15b.png"><img alt="Circle diagram for the fixed rotor resistance &amp; variable reactance - option b" class="alignnone size-full wp-image-161119" height="300" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15b.png" width="158"/></a>
C. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15c.png"><img alt="Circle diagram for the fixed rotor resistance &amp; variable reactance - option c" class="alignnone size-full wp-image-161120" height="300" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15c.png" width="158"/></a>
D. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15d.png"><img alt="Circle diagram for the fixed rotor resistance &amp; variable reactance - option d" class="alignnone size-full wp-image-161121" height="158" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15d.png" width="300"/></a>
Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15b.png"><img alt="Circle diagram for the fixed rotor resistance &amp; variable reactance - option b" class="alignnone size-full wp-image-161119" height="300" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q15b.png" width="158"/></a>
Discussion
3.

If the no load test is conducted at its rated frequency but less than the rated voltage, then the mechanical losses will _____ and the constant losses will _________

A. constant, reduce
B. constant, rise
C. reduce, rise
D. constant, constant
Answer» B. constant, rise
Discussion
4.

If the no load test is conducted at its rated frequency but less than the rated voltage, then the wattmeter reading will be ____________

A. reduced
B. more than previous reading
C. remain same
D. none of the mentioned
Answer» B. more than previous reading
Discussion
5.

Stator resistance can be measured using Kelvin s double bridge.

A. True
B. False
Answer» B. False
Discussion
6.

Blocked rotor test is conducted to find the ____________

A. leakage impedance
B. leakage reactance
C. stator impedance
D. rotor impedance
Answer» B. leakage reactance
Discussion
7.

The rotor mmf per pole in the 3-phase, 4-pole induction motor varied with slip is?

A. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6a.png"><img alt="The rotor mmf per pole in the 3-phase, 4-pole induction motor varied with slip - option a" class="alignnone size-full wp-image-161110" height="231" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6a.png" width="300"/></a>
B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6b.png"><img alt="The rotor mmf per pole in the 3-phase, 4-pole induction motor varied with slip - option b" class="alignnone size-full wp-image-161111" height="221" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6b.png" width="300"/></a>
C. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6c.png"><img alt="The rotor mmf per pole in the 3-phase, 4-pole induction motor varied with slip - option c" class="alignnone size-full wp-image-161113" height="216" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6c.png" width="300"/></a>
D. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6d.png"><img alt="The rotor mmf per pole in the 3-phase, 4-pole induction motor varied with slip - option d" class="alignnone size-full wp-image-161114" height="235" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6d.png" width="277"/></a>
Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6b.png"><img alt="The rotor mmf per pole in the 3-phase, 4-pole induction motor varied with slip - option b" class="alignnone size-full wp-image-161111" height="221" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q6b.png" width="300"/></a>
Discussion
8.

In a 3-phase induction motor, the flux per pole will vary with the slip is?

A. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5a.png"><img alt="The flux per pole will vary with the slip in a 3-phase induction motor - option a" class="alignnone size-full wp-image-161104" height="208" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5a.png" width="300"/></a>
B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5b.png"><img alt="The flux per pole will vary with the slip in a 3-phase induction motor - option b" class="alignnone size-full wp-image-161105" height="231" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5b.png" width="300"/></a>
C. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5c.png"><img alt="The flux per pole will vary with the slip in a 3-phase induction motor - option c" class="alignnone size-full wp-image-161107" height="221" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5c.png" width="300"/></a>
D. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5d.png"><img alt="The flux per pole will vary with the slip in a 3-phase induction motor - option d" class="alignnone size-full wp-image-161108" height="216" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5d.png" width="300"/></a>
Answer» B. <a href="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5b.png"><img alt="The flux per pole will vary with the slip in a 3-phase induction motor - option b" class="alignnone size-full wp-image-161105" height="231" src="https://www.sanfoundry.com/wp-content/uploads/2017/05/electrical-machines-questions-answers-circle-diagrams-induction-machines-q5b.png" width="300"/></a>
Discussion
9.

A 10kW, 50 Hz, 3-phase induction motor develops the rated torque at 1440rpm. If the load torque is reduced to half, then the power output that can now be obtained is?

A. 5 kW
B. 5.3 KW
C. 4.6 kW
D. 8 kW
Answer» B. 5.3 KW
Discussion
10.

A 10kW, 50 Hz, 3-phase induction motor develops the rated torque at 1440rpm. If the load torque is reduced to half, then the motor speed is?

A. 1470rpm
B. 1410rpm
C. 1400rpm
D. 1444rpm
Answer» B. 1410rpm
Discussion
11.

Circle diagram depicts the relation between ____________

A. stator current and the slip variation
B. rotor current and stator current
C. slip variation and the power factor
D. slip variation and the losses of the machine
Answer» B. rotor current and stator current
Discussion
12.

Circle diagram of an induction motor is graphical representation of ____________

A. its equivalent circuit
B. its rotor equivalent
C. its stator equivalent
D. its stationary equivalent circuit
Answer» B. its rotor equivalent
Discussion