Power Electronics MCQs

Welcome to our comprehensive collection of Multiple Choice Questions (MCQs) on Power Electronics, a fundamental topic in the field of Electronics and Communication Engineering. Whether you're preparing for competitive exams, honing your problem-solving skills, or simply looking to enhance your abilities in this field, our Power Electronics 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 Power Electronics mcq questions that explore various aspects of Power Electronics problems. Each MCQ is crafted to challenge your understanding of Power Electronics principles, enabling you to refine your problem-solving techniques. Whether you're a student aiming to ace Electronics and Communication Engineering tests, a job seeker preparing for interviews, or someone simply interested in sharpening their skills, our Power Electronics MCQs are your pathway to success in mastering this essential Electronics and Communication Engineering topic.

Note: Each of the following question comes with multiple answer choices. Select the most appropriate option and test your understanding of Power Electronics. 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 Power Electronics knowledge to the test? Let's get started with our carefully curated MCQs!

Power Electronics MCQs | Page 9 of 42

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Q81.
A chopper

a.

converts constant voltage dc into ac and then into variable voltage dc

b.

converts constant voltage dc into variable voltage dc directly

c.

converts ac of one frequency into ac of another frequency

d.

converts ac to dc

Discuss
Answer: (b).converts constant voltage dc into variable voltage dc directly
Q82.
Assertion (A): If the duty cycle of chopper is low the current would not become discontinuous

Reason (R): If the time constant L/R of the load in chopper is low the current may become discontinuous.

a.

Both A and R are correct and R is correct explanation of A

b.

Both A and R correct but R is not correct explanation of A

c.

A is correct but R is wrong

d.

A is wrong but R is correct

Discuss
Answer: (c).A is correct but R is wrong
Q83.
In a single phase full wave regulator, the firing angles in the positive and negative half cycles are generally

a.

equal

b.

different

c.

equal or different

d.

different but sometimes equal

Discuss
Answer: (a).equal
Q84.
An electric heater is controlled by thyristors through on-off control. If α = 0.4, the heating is

a.

16% maximum

b.

40% of maximum

c.

60% of maximum

d.

84% of maximum

Discuss
Answer: (b).40% of maximum
Q85.
A single phase half wave controlled rectifier circuit has a free wheeling diode. The load is a combination of R and L. The firing angle is α. The period of conduction of SCR and free wheeling diode respectively are

a.

α < ωt < π and π < ωt < (2π + α)

b.

α < ωt < π and π < ωt < 2π

c.

α < ωt < (π + α) and (π + α) < ωt < 2π

d.

α < ωt < π and π < ωt < (2π - α)

Discuss
Answer: (a).α < ωt < π and π < ωt < (2π + α)
Q86.
Assertion (A): A transistor requires a continuous base signal for conduction but a thyristor requires a gate pulse.

Reason (R): Transistor find widespread application in power electronic circuits.

a.

Both A and R are correct and R is correct explanation of A

b.

Both A and R correct but R is not correct explanation of A

c.

A is correct but R is wrong

d.

A is wrong but R is correct

Discuss
Answer: (c).A is correct but R is wrong
Q87.
In a thyristor the gate current is increased, then

a.

anode current will increase

b.

anode current will decrease

c.

anode current will remain constant

d.

anode current may increase or decrease

Discuss
Answer: (c).anode current will remain constant
Q88.
Thyristors are not suitable for logic circuits.

a.

True

b.

False

c.

May be True or False

d.

Can't say

Discuss
Answer: (b).False
Q89.
In a circuit using a full wave converter (M - 2 connection) the PIV of each thyristor is 400 V. For the same output voltage and fully controlled bridge converter, PIV will be

a.

400 V

b.

800 V

c.

200 V

d.

200√2 V

Discuss
Answer: (c).200 V
Q90.
A dc separately excited motor has constant field current. The armature is fed from a single phase supply through a full converter. When α = 0, speed is 500 rpm. If α = 45°, the speed is likely to be

a.

about 350 rpm

b.

about 250 rpm

c.

about 175 rpm

d.

about 125 rpm

Discuss
Answer: (d).about 125 rpm
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