A thyristor equivalent of a thyratron tube is a _________?

Related Mcqs:

1. 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)

2. The capacitance of reversed bised junction J2 in a thyristor is CJ2 = 20 pF and can be assumed to be independant of the off state voltage. The limiting value of the charging current to turn on the thyristor is 16 mA. What is the critical value of dv/dt?

   A. 600 V/µs
   B. 800 V/µs
   C. 1200 V/µs
   D. 1000 V/µs

3. 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.

4. Thyristor can be protected from over voltages by using____________?

   A. voltage clamping device.
   B. fuse.
   C. heat sink.
   D. snubber circuit.

5. 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

6. 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

7. Thyristor is nothing but a____________?

   A. Controlled transistor
   B. Controlled switch
   C. Amplifier with higher gain
   D. Amplifier with large current gain

8. A thyristor can termed as__________?

   A. AC switch
   B. DC switch
   C. Both a and B
   D. Square wave switch

9. During which time maximum conduction spreading take place in the thyristor during turn ON?

   A. Delay time
   B. Spread time
   C. Rise time
   D. Same for every case

10. 60 thyrsistors are connected in series and parallel to form a 10 KV and 5.5 KA switch. Each thyristor is rated for 1.2 KV, 1 KA. The no. of parallel path are 6. The efficiency of the switch is______________________?

    A. 76.3 %
    B. 91.6 %
    C. 83.3 %
    D. 90.9 %