ESE 2021 Technical Quiz || Thyristor & Their Characteristics, Application of Diodes & Thyristor in Circuit

A resistor is connected across the gate cathode terminal of a thyristor increases its

1) dv/dt rating

2) holding current

3) noise immunity

4) turn off time

Consider the following statements about diodes:

1. Reverse recovery time of Schottky diodes is of the order of nanoseconds.

2. Gold or platinum is doped in the layers of fast recovery diodes of fast recovery diodes.

3. Fast recovery diodes operator faster than Schottky diodes.

Which of the above statements are correct?

In given voltage commutation circuit, Vs = 230 V then What will be the peak inverse voltage across free wheel diode and main thyristor respectively?

The magnitude of Anode current will increase in a thyristor when it’s gate current is

Figure shows a thyristor controlling power in a load resistance R_L. The supply voltage is 240 V dc and the limit for di/dt is 50 A/µs. When R_s=5 Ω, the minimum value of L (in µH) needed for protection is