Explore topic-wise MCQs in Electrical Machines.

This section includes 20 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.

For a 220-V level compound generator the terminal voltage at the half load is?

A. more than 220-V
B. same as no-load voltage
C. more than no-load voltage
D. lesser than no-load voltage
Answer» C. more than no-load voltage
2.

Mark the correct order for the external characteristics of compound generators from the below graph.

A. 1: over compound, 2: level compound, 3: under compound, 4: differential compound
B. 1: under compound, 2: level compound, 3: over compound, 4: differential compound
C. 1: differential compound, 2: level compound, 3: under compound, 4: over compound
D. 1: over compound, 2: differential compound, 3: under compound, 4: level compound
Answer» B. 1: under compound, 2: level compound, 3: over compound, 4: differential compound
3.

The voltage drop in terminal voltage from no-load to full load in a shunt generator can be compenated using _________

A. aiding series field
B. long-shunt, diferential field
C. aiding shunt field
D. any of the measures
Answer» B. long-shunt, diferential field
4.

Identify the machines by observing their external characteristics for (i) and (ii) respectively.(i) (ii)

A. Separately excited dc generator, shunt generator
B. Shunt generator, separately excited dc generator
C. Differentially compound dc generator, separately excited
D. Series dc generator, shunt generator
Answer» B. Shunt generator, separately excited dc generator
5.

For a given dc generator, the external characteristic is plotted. Without using further plots, how can we obtain internal characteristic?

A. By adding the IaRa drop to the plot
B. By adding armature reaction
C. By reducing IaRa drop
D. All of the mentioned
Answer» B. By adding armature reaction
6.

The air gap line represents _________

A. magnetic behaviour of the air gap of the dc machine
B. magnetic behaviour of the air gap of the induction machine
C. magnetic behaviour of the iron core
D. all of the mentioned
Answer» B. magnetic behaviour of the air gap of the induction machine
7.

Armature characteristic is also known as _________

A. regulation characteristic
B. magnetization characteristic
C. external characteristic
D. load characteristic
Answer» B. magnetization characteristic
8.

A student forgot to mark the x-y axes in his experiments but he just noted down the cause and the effect for each. How will he conclude about the armature characteristic out of the all plotted graphs?

A. By marking graph for constant terminal voltage
B. By marking graph for constant field current
C. By marking graph for constant armature current
D. By marking graph for constant speed
Answer» B. By marking graph for constant field current
9.

The external characteristic is plotted between ____________

A. terminal voltage vs armature current at constant excitation
B. terminal voltage vs field current at constant armature current
C. induced armature emf vs armature current at constant excitation
D. none of the mentioned
Answer» B. terminal voltage vs field current at constant armature current
10.

THE_VOLTAGE_DROP_IN_TERMINAL_VOLTAGE_FROM_NO-LOAD_TO_FULL_LOAD_IN_A_SHUNT_GENERATOR_CAN_BE_COMPENATED_USING?$

A. aiding series field
B. long-shunt, diferential field
C. aiding shunt field
D. any of the measures
Answer» B. long-shunt, diferential field
11.

For a 220-V level compound generator the terminal voltage at the half load is

A. more than 220-V
B. same as no-load voltage
C. more than no-load voltage
D. lesser than no-load voltage
Answer» C. more than no-load voltage
12.

What losses occur in the teeth of dc generator?

A. To reduce hysteresis loss
B. To reduce eddy current loss
C. To reduce eddy current as well as hysteresis losses
D. To achieve high permeability
Answer» D. To achieve high permeability
13.

Why is armature of a dc machine made of silicon steel stampings?

A. To reduce hysteresis loss
B. To reduce eddy current loss
C. For the ease with which slots can be created
D. To achieve high permeability
Answer» B. To reduce eddy current loss
14.

For a given dc generator, the external characteristic is plotted . Without using further plots, how can we obtain internal characteristic?

A. By adding the IaRa drop to the plot
B. By adding armature reaction
C. By reducing IaRa drop
D. All of the mentioned
Answer» B. By adding armature reaction
15.

The air gap line represents

A. magnetic behaviour of the air gap of the dc machine
B. magnetic behaviour of the air gap of the induction machine
C. magnetic behaviour of the iron core
D. all of the mentioned
Answer» B. magnetic behaviour of the air gap of the induction machine
16.

Armature characteristic is also known as

A. regulation characteristic
B. magnetization characteristic
C. external characteristic
D. load characteristic
Answer» B. magnetization characteristic
17.

A student forgot to mark the x-y axes in his experiments but he just noted down the cause and the effect for each. How will he conclude about the armature

A.
B. By marking graph for constant terminal voltage
C. By marking graph for constant field current
Answer» B. By marking graph for constant terminal voltage
18.

The external characteristic is plotted between

A. terminal voltage vs armature current at constant excitation
B. terminal voltage vs field current at constant armature current
C. induced armature emf vs armature current at constant excitation
D. none of the mentioned
Answer» B. terminal voltage vs field current at constant armature current
19.

Choose the most inappropriate out of the following for the no-load characteristics of the dc generator.

A. It is the open circuit characteristic of the machine
B. It is magnetization characteristic of the machine
C. It is conducted on the unloaded machine
D. None of the mentioned
Answer» E.
20.

Which of the following characteristics reveal about the magnetization nature of the machine?

A. No-load characteristics
B. Load characteristics
C. Armature characteristics
D. Both no-load and load characteristics
Answer» E.