Electrical Engineering Mcqs

Example of a voltage clamping device______________?

(A) fast acting fuse

(B) snubber circuit

(C) metal oxide varistor

(D) aluminium block

Submitted By: Ali Uppal


Switching frequency of SITH is____________?

(A) 5 KHz

(B) 10 KHz

(C) 60 KHz

(D) 100 KHz

Submitted By: Ali Uppal


Practical way of obtaining static voltage equalization in series connected SCRs is by the use of____________?

(A) One resistor across the string

(B) Resistors of the same value across each SCR

(C) Resistors of different values across each SCR

(D) One resistor in series with each SCR

Submitted By: Ali Uppal


Thyristor can be protected from over voltages by using____________?

(A) voltage clamping device.

(B) fuse.

(C) heat sink.

(D) snubber circuit.

Submitted By: Ali Uppal


BCT is used for____________?

(A) High power phase control

(B) High power current control

(C) Low power current control

(D) Low power phase control

Submitted By: Ali Uppal


Let of a thyristor Vc1, Vc2, Vc3 are forward break over voltage for gate current Ig1, Ig2, Ig3 respectively. Then________________?

(A) Vc1 > Vc2 > Vc3 when Ig1 > Ig2 > Ig3.

(B) Vc1 > Vc2 > Vc3 when Ig1 < Ig2 < Ig3.

(C) Vc1 = Vc2 = Vc3 any value of Ig.

(D) Vc1 > Vc2 > Vc3 when Ig1 ≥ Ig2 &Atil

Submitted By: Ali Uppal


Submitted By: Ali Uppal


Which triggering is the most reliable____________?

(A) Forward voltage triggering

(B) Gate triggering

(C) dV / dt triggering

(D) Thermal triggering

Submitted By: Ali Uppal


Leakage current flows through the thyristor in_________?

(A) forward blocking mode

(B) reverse blocking mode

(C) both forward and reverse blocking mode

(D) forward conduction mode

Submitted By: Ali Uppal


Which of the following is disadvantage of fast recovery diodes?

(A) Recovery is only 5 µs

(B) Recovery is only 50 µs

(C) Doping is carried out

(D) None of these

Submitted By: Ali Uppal