Electrical Engineering Mcqs

When a large surge current of very short duration flows through a thyristor then which one of the following device will operate to protect the thyristor ___________?

(A) CB

(B) Snubber circuit

(C) Voltage clamping device

(D) Fast acting current limiting device (FACL fuse)

Submitted By: Ali Uppal


A power semiconductor may undergo damage due to____________?

(A) High di/dt

(B) High dv/dt

(C) Low di/dt

(D) Low dv/dt

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CB used for over current protection of thyristor operates when the fault current is__________?

(A) of long period

(B) of short duration

(C) both (A) and (B)

(D) neither (A) nor (B)

Submitted By: Ali Uppal


Submitted By: Ali Uppal


Submitted By: Ali Uppal


Materials used in heat sink should have_____________?

(A) high thermal conductivity

(B) large surface area

(C) high melting point

(D) All of these

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A thyristor can termed as__________?

(A) AC switch

(B) DC switch

(C) Both a and B

(D) Square wave switch

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Which of the following is used in heat sink_____________?

(A) Iron

(B) Aluminium

(C) Carbon

(D) Silver

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How can we protect SCR from thermal conditions _____________?

(A) Use of snubber circuit.

(B) Using heat sink.

(C) Using CB and fuse.

(D) Using equalizing circuit

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Thyristor is nothing but a____________?

(A) Controlled transistor

(B) Controlled switch

(C) Amplifier with higher gain

(D) Amplifier with large current gain

Submitted By: Ali Uppal