Explore topic-wise MCQs in Design Electrical Machines.

This section includes 20 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.

High value of the specific electric loading can be used for low voltage machines.

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

How many factors influence the choice of specific electric loading?

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

What is the range of the air gap density for salient pole machines?

A. 0.52-0.65 Wb per m2
B. 0.5-0.6 Wb per m2
C. 0.54-0.65 Wb per m2
D. 0.44-0.65 Wb per m2
Answer» B. 0.5-0.6 Wb per m2
Discussion
4.

The machines having high air gap density operates poorly when connected in synchronism.

A. true
B. false
Answer» C.
Discussion
5.

What is the formula for output equations in synchronous machines?

A. kVA output = output coefficient * diameter2 * length * synchronous speed
B. kVA output = output coefficient / diameter2 * length * synchronous speed
C. kVA output = output coefficient * diameter2 / length * synchronous speed
D. kVA output = output coefficient * diameter2 * length / synchronous speed
Answer» B. kVA output = output coefficient / diameter2 * length * synchronous speed
Discussion
6.

THE_MACHINES_HAVING_HIGH_AIR_GAP_DENSITY_OPERATES_POORLY_WHEN_CONNECTED_IN_SYNCHRONISM??$

A. true
B. false
Answer» C.
Discussion
7.

How many factors influence the choice of specific electric loading?$

A. 2
B. 3
C. 4
D. 5
Answer» D. 5
Discussion
8.

What is the range of the air gap density for salient pole machines?$

A. 0.52-0.65 Wb per m<sup>2</sup>
B. 0.5-0.6 Wb per m<sup>2</sup>
C. 0.54-0.65 Wb per m<sup>2</sup>
D. 0.44-0.65 Wb per m<sup>2</sup>
Answer» B. 0.5-0.6 Wb per m<sup>2</sup>
Discussion
9.

What is the value of specific electric loading for the salient pole alternators?

A. 20,000-40,000 A per m
B. 50,000-75,000 A per m
C. 25,000-40,000 A per m
D. 20,000-45,000 A per m
Answer» B. 50,000-75,000 A per m
Discussion
10.

How is the specific electric loading related to the synchronous reactance of the machines?

A. specific electric loading is high, leakage reactance is high, giving low synchronous reactance
B. specific electric loading is high, leakage reactance is low, giving low synchronous reactance
C. specific electric loading is high, leakage reactance is high, giving high synchronous reactance
D. specific electric loading is low, leakage reactance is high, giving high synchronous reactance
Answer» D. specific electric loading is low, leakage reactance is high, giving high synchronous reactance
Discussion
11.

High value of the specific electric loading can be used for low voltage machines?

A. true
B. false
Answer» B. false
Discussion
12.

How is the specific electric loading related to copper losses and temperature rise?

A. high specific electric loading gives high copper losses and high temperature rise
B. high specific electric loading gives low copper losses and high temperature rise
C. high specific electric loading gives high copper losses and low temperature rise
D. high specific electric loading gives low copper losses and low temperature rise
Answer» B. high specific electric loading gives low copper losses and high temperature rise
Discussion
13.

How is the steady state stability related with the air gap density?

A. air gap density is directly proportional to the steady state stability
B. air gap density is indirectly proportional to the steady state stability
C. air gap density is directly proportional to the square of the steady state stability
D. air gap density is directly proportional to the square of the steady state stability
Answer» B. air gap density is indirectly proportional to the steady state stability
Discussion
14.

How is the transient short circuit current related with the air gap density?

A. air gap density is directly proportional to the short circuit current
B. air gap density is indirectly proportional to the short circuit current
C. air gap density is directly proportional to the square of the short circuit current
D. air gap density is directly proportional to the square of the short circuit current
Answer» B. air gap density is indirectly proportional to the short circuit current
Discussion
15.

How is the voltage related with the air gap density?

A. air gap density is directly proportional to the voltage
B. air gap density is indirectly proportional to the voltage
C. air gap density is directly proportional to the square of the voltage
D. air gap density is indirectly proportional to the square of the voltage
Answer» C. air gap density is directly proportional to the square of the voltage
Discussion
16.

How is the iron loss related with the choice of specific magnetic loading?

A. choice of magnetic loading is directly proportional to the iron loss
B. choice of magnetic loading is indirectly proportional to the iron loss
C. choice of magnetic loading is directly proportional to the square of the iron loss
D. choice of magnetic loading is indirectly proportional to the square of the iron loss
Answer» B. choice of magnetic loading is indirectly proportional to the iron loss
Discussion
17.

How many factors does the choice of specific magnetic loading depend upon?

A. 4
B. 2
C. 5
D. 8
Answer» D. 8
Discussion
18.

What is the formula for the output equation with respect to the peripheral speed?

A. output = 1.11* specific magnetic loading * specific electrical loading * winding space factor * 10<sup>-3</sup> * peripheral speed<sup>2</sup> *Length * synchronous speed
B. output = 1.11* specific magnetic loading * specific electrical loading * winding space factor * 10<sup>-3</sup> * peripheral speed<sup>2</sup> *Length / synchronous speed
C. output = 1.11* specific magnetic loading * specific electrical loading * winding space factor / 10<sup>-3</sup> * peripheral speed<sup>2</sup> *Length * synchronous speed
D. output = 1.110 / specific magnetic loading * specific electrical loading * winding space factor * 10<sup>-3</sup> * peripheral speed<sup>2</sup> *Length * synchronous speed
Answer» C. output = 1.11* specific magnetic loading * specific electrical loading * winding space factor / 10<sup>-3</sup> * peripheral speed<sup>2</sup> *Length * synchronous speed
Discussion
19.

What is the formula of the output coefficient?

A. output coefficient = 11 * specific magnetic loading / specific electrical loading * winding space factor * 10<sup>-3</sup>
B. output coefficient = 11 / specific magnetic loading * specific electrical loading * winding space factor * 10<sup>-3</sup>
C. output coefficient = 11 * specific magnetic loading * specific electrical loading * winding space factor * 10<sup>-3</sup>
D. output coefficient = 11 * specific magnetic loading * specific electrical loading / winding space factor * 10<sup>-3</sup>
Answer» D. output coefficient = 11 * specific magnetic loading * specific electrical loading / winding space factor * 10<sup>-3</sup>
Discussion
20.

What is the formula for output equation in synchronous machines?

A. kVA output = output coefficient * diameter2 * length * synchronous speed
B. kVA output = output coefficient / diameter2 * length * synchronous speed
C. kVA output = output coefficient * diameter2 / length * synchronous speed
D. kVA output = output coefficient * diameter2 * length / synchronous speed
Answer» B. kVA output = output coefficient / diameter2 * length * synchronous speed
Discussion