Explore topic-wise MCQs in Design Electrical Machines.

This section includes 17 Mcqs, each offering curated multiple-choice questions to sharpen your Design Electrical Machines knowledge and support exam preparation. Choose a topic below to get started.

1.

What is the formula for the area of the ring?

A. area of the ring = depth of the end ring + thickness of the end ring
B. area of the ring = depth of the end ring – thickness of the end ring
C. area of the ring = depth of the end ring / thickness of the end ring
D. area of the ring = depth of the end ring * thickness of the end ring
Answer» E.
Discussion
2.

How is the current density of the rotor bars chosen with respect to the end rings?

A. current density of rotor bars < current density of end rings
B. current density of rotor bars > current density of end rings
C. current density of rotor bars = current density of end rings
D. current density of rotor bars <= current density of end rings
Answer» B. current density of rotor bars > current density of end rings
Discussion
3.

The value of the current density is chosen for the end rings such that the desired value of rotor resistance is obtained.

A. true
B. false
Answer» B. false
Discussion
4.

What is the formula for the rms value of the end ring current?

A. rms value of end ring current = (bars per pole * current per bar) / (3.14*no of poles)
B. rms value of end ring current = (bars per pole * current per bar) * (3.14*no of poles)
C. rms value of end ring current = (bars per pole * current per bar) / (no of poles)
D. rms value of end ring current = (bars per pole * current per bar) / (3.14+no of poles)
Answer» B. rms value of end ring current = (bars per pole * current per bar) * (3.14*no of poles)
Discussion
5.

The end resistance, if not negligible, will tend to distort the bar current distribution from being sinusoidal.

A. true
B. false
Answer» B. false
Discussion
6.

WHAT_IS_THE_FORMULA_FOR_THE_RMS_VALUE_OF_THE_END_RING_CURRENT??$

A. rms value of end ring current = (bars per pole * current per bar) / (3.14*no of poles)
B. rms value of end ring current = (bars per pole * current per bar) * (3.14*no of poles)
C. rms value of end ring current = (bars per pole * current per bar) / (no of poles)
D. rms value of end ring current = (bars per pole * current per bar) / (3.14+no of poles)
Answer» B. rms value of end ring current = (bars per pole * current per bar) * (3.14*no of poles)
Discussion
7.

How is the current density of the rotor bars chosen with respect to the end rings?$

A. current density of rotor bars < current density of end rings
B. current density of rotor bars > current density of end rings
C. current density of rotor bars = current density of end rings
D. current density of rotor bars <= current density of end rings
Answer» B. current density of rotor bars > current density of end rings
Discussion
8.

The_value_of_the_current_density_is_chosen_for_the_end_rings_such_that_the_desired_value_of_rotor_resistance_is_obtained?$

A. true
B. false
Answer» B. false
Discussion
9.

What_is_the_formula_for_the_area_of_the_ring?

A. area of the ring = depth of the end ring + thickness of the end ring
B. area of the ring = depth of the end ring – thickness of the end ring
C. area of the ring = depth of the end ring / thickness of the end ring
D. area of the ring = depth of the end ring * thickness of the end ring
Answer» E.
Discussion
10.

What is the formula for the maximum current through each bar?

A. maximum value of the current through each bar = 2 * current through each bar
B. maximum value of the current through each bar = (2 * current through each bar)1/2
C. maximum value of the current through each bar = (2 * current through each bar)2
D. maximum value of the current through each bar = (2 * current through each bar)1/3
Answer» C. maximum value of the current through each bar = (2 * current through each bar)2
Discussion
11.

What is the formula for the maximum value of current through end ring, when the current is not maximum in all the bars under one pole at the same time?

A. maximum current in end ring= (2*3.14) / (bars per pole/2*no of poles) * current per bar
B. maximum current in end ring= (2/3.14) * (bars per pole/2*no of poles) / current per bar
C. maximum current in end ring= (2*3.14) * (bars per pole/2*no of poles) * current per bar
D. maximum current in end ring= (2*3.14) / (bars per pole/2*no of poles) / current per bar
Answer» D. maximum current in end ring= (2*3.14) / (bars per pole/2*no of poles) / current per bar
Discussion
12.

Given the bars per pole is 6 and the current per bar is 20 A, what is the value of the maximum current in the end rings?

A. 60 A
B. 80 A
C. 90 A
D. 70 A
Answer» B. 80 A
Discussion
13.

What is the formula for the maximum current in end ring, if the current in all bars are maximum at the same time?

A. maximum current in the end ring= bars per pole * 2 * current per bar
B. maximum current in the end ring= (bars per pole / 2) * current per bar
C. maximum current in the end ring= bars per pole / 2 / current per bar
D. maximum current in the end ring= bars per pole * 2 / current per bar
Answer» C. maximum current in the end ring= bars per pole / 2 / current per bar
Discussion
14.

The end resistance, if not negligible, will tend to distort the bar current distribution from being sinusoidal?

A. true
B. false
Answer» B. false
Discussion
15.

What factors does the current in the bars depend on?

A. emfs, position of bars in magnetic field
B. instantaneous emfs, position of bars in magnetic field
C. emf
D. instantaneous emf
Answer» C. emf
Discussion
16.

What happens if the resistance of the end rings is negligible?

A. resistance coming in each current path is resistance of three bars
B. resistance coming in each current path is resistance of four bars
C. resistance coming in each current path is resistance of two bars
D. resistance coming in each current path is resistance of five bars
Answer» D. resistance coming in each current path is resistance of five bars
Discussion
17.

How does the revolving field produce emf in the bars?

A. revolving field produces emf of fundamental frequency in the bars
B. revolving field produces emf of third frequency in the bars
C. revolving field produces emf of no frequency in the bars
D. revolving field produces emf of sinusoidal frequency in the bars
Answer» B. revolving field produces emf of third frequency in the bars
Discussion