The typical value of SCR for modern alternator is____________?

A. 1.5.
B. 0.5.
C. 1.0.
D. 1.2.

An SCR is considered to be a semi controlled device because_______?

A. It can be turned off but not on with a gate pulse.
B. It conducts only during one half cycle of an alternating current wave.
C. It can be turned on but not off with a gate pulse.
D. It can be turned on only during one half cycle of an ac.

A single phase full bridge inverter can operated in load commutation mode in case load consist of______?

A. Rl.
B. Rlc underdamped.
C. Rlc overdamped.
D. Rlc critically damped

A single phase one pulse controlled circuit has a resistance R and counter emf E load 400 sin(314 t) as the source voltage. For a load counter emf of 200 V, the range of firing angle control is _____?

A. 30° to 150°.
B. 30° to 180°.
C. 60° to 120°.
D. 60° to 180°.

Which statement is true for latching current ___________?

A.iT is related to turn off process of the device.
B. It is related to conduction process of device.
C. It is related to turn on process of the device.
D. Both c and d.

If holding current of a thyristor is 2 mA then latching current should be_____?

A. 0.01 a.
B. 0.002 a.
C. 0.009 a.
D. 0.004 a.

In reverse blocking mode of a thyristor______?

A. Junction j2 is in reverse bias and j1, j3 is in forward bias.
B. Junction j3 is in forward bias and j1, j2 in reverse bias.
C. Junction j1, j3 is in reverse bias and j2 is in forward bias.
D. Junction j1 and j2 is in forward bias and j3 is in reverse bias.

In forward blocking mode of a thyristor________?

A. Junction j2 is in reverse bias and j1, j3 is in forward bias.
B. Junction j3 is in forward bias and j1, j2 is in reverse bias.
C. Junction j1, j3 is in reverse bias and j2 is in forward bias.
D. Junction j1 and j2 is in forward bias and j3 is in reverse bias.

For an SCR gate – cathode characteristic is a straight line of 130. For triggered source volume of 15 V and allowable gate power dissipation of 0.5 W compute the gate source resistance_____?

A. 111.9 ãžâ©.
B. 11.19 ãžâ©.
C. 108 ãžâ©.
D. 115 ãžâ©

The function of snubber circuit connected across the SCR is to___________?

A. Suppress dv / dt.
B. Increase dv / dt.
C. Decrease dv / dt.
D. Decrease di / dt.