Which of the following is used in SCR to protect from high dV / dt__________________?

Related Mcqs:

1. The turn-on time of an SCR with inductive load is 20 µs. The puls train frequency is 2.5 KHz with a mark/space ratio of 1/10, then SCR will___________?

   A. Turn on
   B. Not turn on
   C. Turn on if inductance is removed
   D. Turn on if pulse frequency us increased to two times

2. What is used to protect the SCR from over current ________________?

   A. CB and fuse.
   B. Heat sink.
   C. Snubber circuit.
   D. Voltage clamping device.

3. 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

4. What is used to protect a thyristor from high di / dt conditions__________?

   A. Fuse.
   B. Snubber circuit
   C. Inductor
   D. Voltage clamping device

5. 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 Ω.
   B. 11.19 Ω.
   C. 108 Ω.
   D. 115 Ω

6. Maximum di / dt in a SCR is________?

   A. Directly proportional to Vm of supply voltage
   B. Inversely proportional to Vm of supply voltage
   C. Inversely proportional to L in the circuit
   D. Both A and C

7. Anode of an operational SCR is _______________?

   A. Always positive w.r.t cathode
   B. Always negative w.r.t anode
   C. Always positive w.r.t anode
   D. Always negative w.r.t cathode

8. In the operation and control of both naturally commutated and forced commutated SCR base converter, commutation plays an important role. The converters is / are ___________?

   A. AC – DC
   B. DC – DC
   C. DC – AC
   D. All of these

9. An SCR can be used___________?

   A. as static conductor
   B. for power control
   C. for speed control of dc shunt motor
   D. All of these

10. If all the SCR’s of 3 phase PAC is replaced by diodes, they would be triggered_____________?

    A. 120 degree after the zero crossing of the corresponding line voltages
    B. 60 degree after the zero crossing of the corresponding line voltages
    C. 120 degree before the zero crossing of the corresponding line voltages
    D. 60 degree before the zero crossing of the corresponding line voltages