DC Motors MCQs

Welcome to our comprehensive collection of Multiple Choice Questions (MCQs) on DC Motors, a fundamental topic in the field of DC Machines. Whether you're preparing for competitive exams, honing your problem-solving skills, or simply looking to enhance your abilities in this field, our DC Motors MCQs are designed to help you grasp the core concepts and excel in solving problems.

In this section, you'll find a wide range of DC Motors mcq questions that explore various aspects of DC Motors problems. Each MCQ is crafted to challenge your understanding of DC Motors principles, enabling you to refine your problem-solving techniques. Whether you're a student aiming to ace DC Machines tests, a job seeker preparing for interviews, or someone simply interested in sharpening their skills, our DC Motors MCQs are your pathway to success in mastering this essential DC Machines topic.

Note: Each of the following question comes with multiple answer choices. Select the most appropriate option and test your understanding of DC Motors. You can click on an option to test your knowledge before viewing the solution for a MCQ. Happy learning!

So, are you ready to put your DC Motors knowledge to the test? Let's get started with our carefully curated MCQs!

DC Motors MCQs | Page 3 of 13

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Q21.
All others are advantages of DC motor over AC motor except _______________

a.

Low cost

b.

Wide speed range

c.

Stability

d.

High starting torque

Discuss
Answer: (a).Low cost
Q22.
If a DC motor designed for 45°C ambient temperature is to be used for 55°C ambient temperature, then the motor ___________

a.

Of lower HP should be selected

b.

Of higher HP should be selected

c.

Can be used for 50°C ambient temperature also

d.

Is to be de-rated by a factor recommended by manufacturer and select the next higher H.P. motor

Discuss
Answer: (d).Is to be de-rated by a factor recommended by manufacturer and select the next higher H.P. motor
Q23.
Torque developed by a DC motor depends upon _____________

a.

magnetic field

b.

active length of the conductor

c.

current flow through the conductors

d.

Current, active length, no. of conductors, magnetic field all

Discuss
Answer: (d).Current, active length, no. of conductors, magnetic field all
Q24.
For very sensitive and wide speed control, which of the following method is preferred?

a.

Armature control

b.

Ward-Leonard control

c.

Multiple voltage control

d.

Field control

Discuss
Answer: (b).Ward-Leonard control
Q25.
Field weakening control method is used for the speed _________

a.

Above rated speed

b.

Below rated speed

c.

Can be used anywhere

d.

Can’t tell

Discuss
Answer: (a).Above rated speed
Q26.
Armature resistance control method is used for the speed _____________

a.

Above rated speed

b.

Below rated speed

c.

Can be used anywhere

d.

Can’t tell

Discuss
Answer: (b).Below rated speed
Q27.
Which function is performed by counter emf of a DC motor?

a.

Exceeds supply voltage

b.

Aids applied voltage

c.

Helps in energy conversion

d.

Regulates its armature voltage

Discuss
Answer: (c).Helps in energy conversion
Q28.
The output power of any electrical (AC or DC) motor is taken from the ______________

a.

Field

b.

Coupling mounted on the shaft

c.

Armature

d.

Motor frame

Discuss
Answer: (b).Coupling mounted on the shaft
Q29.
Why field winding of a DC series motor is provided with thick wire?

a.

As it carries large load current

b.

To provide large flux

c.

In order to reduce eddy current to provide large flux

d.

To reduce the of insulting materials

Discuss
Answer: (a).As it carries large load current
Q30.
Why starters are required in a DC motor?

a.

Back emf of these motors is zero initially

b.

These motors are not self-starting

c.

These motors have high starting torque

d.

To restrict armature current as there is no back emf at starting

Discuss
Answer: (d).To restrict armature current as there is no back emf at starting
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