Explore topic-wise MCQs in Design Electrical Machines.

This section includes 24 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.

The loss for the sleeve bearing having stator outer diameter 150 mm and 1000 rpm is 3.7 W.

A. true
B. false
Answer» B. false
Discussion
2.

The high values actually apply for the small motors below 150 W.

A. true
B. false
Answer» C.
Discussion
3.

What are the factors which result in the bearing friction and windage loss?

A. ball bearings
B. sleeve bearing
C. ball bearing and sleeve bearing
D. ball bearing or sleeve bearing
Answer» E.
Discussion
4.

What is the range of the multiplying factor when test data is not available?

A. 1.7-2
B. 1.75-2.2
C. 1.6-2.3
D. 1.5-2
Answer» C. 1.6-2.3
Discussion
5.

What is the relation between total iron loss for induction motors and the sum of stator tooth and core loss?

A. total iron loss for induction motors = 1.3-2.3 times the sum of stator tooth and core loss
B. total iron loss for induction motors = 1.4-2.4 times the sum of stator tooth and core loss
C. total iron loss for induction motors = 1.5-2.5 times the sum of stator tooth and core loss
D. total iron loss for induction motors = 1.3-2 times the sum of stator tooth and core loss
Answer» D. total iron loss for induction motors = 1.3-2 times the sum of stator tooth and core loss
Discussion
6.

What factors are considered while calculating iron loss in stator teeth and core?

A. flux densities
B. weights
C. flux densities or weights
D. flux densities and weights
Answer» E.
Discussion
7.

WHAT_FACTORS_ARE_CONSIDERED_WHILE_CALCULATING_IRON_LOSS_IN_STATOR_TEETH_AND_CORE??$

A. flux densities
B. weights
C. flux densities or weights
D. flux densities and weights
Answer» E.
Discussion
8.

What is the range of the multiplying factor when test data is not available?$

A. 1.7-2
B. 1.75-2.2
C. 1.6-2.3
D. 1.5-2
Answer» C. 1.6-2.3
Discussion
9.

What_is_the_relation_between_total_iron_loss_for_induction_motors_and_the_sum_of_stator_tooth_and_core_loss?$

A. total iron loss for induction motors = 1.3-2.3 times the sum of stator tooth and core loss
B. total iron loss for induction motors = 1.4-2.4 times the sum of stator tooth and core loss
C. total iron loss for induction motors = 1.5-2.5 times the sum of stator tooth and core loss
D. total iron loss for induction motors = 1.3-2 times the sum of stator tooth and core loss
Answer» D. total iron loss for induction motors = 1.3-2 times the sum of stator tooth and core loss
Discussion
10.

What is the formula of the most economical relation between D and L?

A. length = 0.6 * diameter
B. length = 0.5 / diameter
C. length = 0.6 / diameter
D. length = 0.63 * diameter
Answer» E.
Discussion
11.

What is the range of the motor type constant?

A. 1.1-1.3
B. 1.0-1.4
C. 1.1-1.42
D. 1.1-1.5
Answer» D. 1.1-1.5
Discussion
12.

What is the range of the frequency constant?

A. 0.86-1.0
B. 0.82-1.0
C. 0.9-1.0
D. 0.5-1.0
Answer» B. 0.82-1.0
Discussion
13.

The loss for the sleeve bearing having stator outer diameter 150 mm and 1000 rpm is 3.7 W?

A. true
B. false
Answer» B. false
Discussion
14.

The high values actually apply for the small motors below 150 W?

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

What is the friction and windage loss for a 1500 rpm machine?

A. 3-7% of watt output
B. 3-9% of watt output
C. 4-8% of watt output
D. 1-5% of watt output
Answer» D. 1-5% of watt output
Discussion
16.

What_are_the_factors_which_result_in_the_bearing_friction_and_windage_loss?

A. ball bearings
B. sleeve bearing
C. ball bearing and sleeve bearing
D. ball bearing or sleeve bearing
Answer» E.
Discussion
17.

What is the relation between flux densities with respect to saturation factor?

A. flux density is indirectly proportional to the square of the saturation factor
B. flux density is directly proportional to the square of the saturation factor
C. flux density is indirectly proportional to the saturation factor
D. flux density is directly proportional to the saturation factor
Answer» E.
Discussion
18.

What is the range of the saturation factor in the single phase induction motor?

A. 1.1-1.3
B. 1.0-1.2
C. 1.1-1.35
D. 1.2-1.6
Answer» D. 1.2-1.6
Discussion
19.

What is the formula for the saturation factor?

A. saturation factor = total mmf required for the magnetic circuit/mmf required for air gap
B. saturation factor = total mmf required for the magnetic circuit + mmf required for air gap
C. saturation factor = total mmf required for the magnetic circuit – mmf required for air gap
D. saturation factor = total mmf required for the magnetic circuit * mmf required for air gap
Answer» B. saturation factor = total mmf required for the magnetic circuit + mmf required for air gap
Discussion
20.

What is the formula for the mmf required for air gap?

A. mmf required for air gap = 8,00,000 * air gap flux density * air gap constant / air gap length
B. mmf required for air gap = 8,00,000 * air gap flux density * air gap constant * air gap length
C. mmf required for air gap = 8,00,000 * air gap flux density / air gap constant * air gap length
D. mmf required for air gap = 8,00,000 / air gap flux density * air gap constant * air gap length
Answer» C. mmf required for air gap = 8,00,000 * air gap flux density / air gap constant * air gap length
Discussion
21.

What is the value of the flux density with respect to average flux density?

A. value of flux density = 1.67 times of average flux density
B. value of flux density = 1.70 times of average flux density
C. value of flux density = 1.60 times of average flux density
D. value of flux density = 1.50 times of average flux density
Answer» B. value of flux density = 1.70 times of average flux density
Discussion
22.

What is the angle at which the value of the flux density should be for the calculation of mmf?

A. 400
B. 600
C. 800
D. 700
Answer» C. 800
Discussion
23.

How many parts does the stator mmf passes through?

A. 3
B. 4
C. 5
D. 6
Answer» D. 6
Discussion
24.

How many factors are present in the operating characteristics?

A. 2
B. 3
C. 4
D. 5
Answer» D. 5
Discussion