DC Motor MCQs with Answers Page-1

DC Motor MCQs with Answers: Following Multiple Choice Questions (MCQs) are based on “DC Motor”. These are related with subject Electrical Machines or Basic Electrical Engineering. This topic is mostly beneficial in the field of Electronics, Electrical and Mechanical Engineering.

Topics: Construction and working of DC motors

These MCQs will be useful in various competitive examinations, entrance examinations, oral examination (Viva voce), certifications and interviews.

MCQ on DC Motor

Que.1 Which of the following is not a part of stator of d.c. motor?
1. armature
2. pole core
3. pole shoe
4. field winding

1. armature
2. commutator
3. shaft
4. pole shoe

Option 4: pole shoe

Explanation:Pole shoe, pole core and field windings are stationary so they are stator assembly.
Que.3__________ is used to determine the direction of rotation of d.c. motor.
2. Lenz law
3. Fleming’s right hand rule
4. Fleming’s left hand rule

Option 4: Fleming's left hand rule

Que.4__________ is used to provide power to the rotor of d.c. motor.
1. Carbon brush
2. Commutator
3. Field magnet
4. Yoke

Option 1: Carbon brush

Que.5In Fleming’s Left Hand rule, thumb indicates the direction of ________.
1. current
2. magnetic field
3. force applied on conductor
4. emf produced

Option 3: force applied on conductor

ii. Interchanging field terminals
1. Only i
2. Both i and ii
3. Either i or ii
4. None of the above

Option 3: Either i or ii

Explanation:The direction of d.c. series motor can be changed by interchanging supply or interchanging field terminals. But only one thing should be done at a time otherwise direction of rotation will not change.
Que.7Which of the following is not a part of field magnets?
1. Field winding
2. Armature
3. Pole shoe
4. Pole core

Option 2: Armature

iii. Copper loss
1. All of the above
2. i and ii only
3. ii and iii only
4. i and iii only

Option 2: i and ii only

Explanation:Copper loss occurs in winding therefore no question about occuring in core.
Que.9 Which of the following are purpose of the yoke in d.c. motor?

i. Acts as frame of the machine

ii. Mechanical support

iii. low reluctance for magnetic flux

1. None of the above
2. only i and ii
3. All of the above
4. only i

Option 3: All of the above

ii. In wave winding number of parallel paths, A=4
1. Both statements are correct.
2. Both statements are wrong.
3. Only statement i is correct.
4. Only statement ii is correct.

Option 3: Only statement i is correct.

Explanation:
In wave winding number of parallel paths are 2.
Que.11If an AC supply is applied to DC motor then
1. it will burn.
2. it will run with lower speed.
3. it will run with normal speed.
4. it will run with higher speed.

Option 1: it will burn.

Que.12While Faraday’s law tells us the __________ of the e.m.f. produced, Lenz’s law tells us the _________ that current will flow.
1. Quality, Opposition
2. Direction, Magnitude
3. Magnitude, Direction
4. Opposition, Quality

Option 3: Magnitude, Direction

Que.13The armature of d.c. motor is laminated _____ .
1. to reduce hysteresis loss
2. to reduce eddy current loss
3. to increase strength
4. All of the above