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___________?

Related Mcqs:

1. Which one is most suitable power device for high frequency (>100 KHz) switching application?

   A. BJT
   B. Power MOSFET
   C. Schottky diode
   D. Microwave transistor

2. For swept frequency measurements, the input impedance of the mismatched transmission line would vary with frequency as the electrical length of the transmission line would

   A. Decrease with frequency
   B. Remains same with change in frequency
   C. Increase with frequency
   D. Either A. or B.

3. 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

4. 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°.

5. A single phase full bridge inverter can operate in load commutation mode in case load consists of____________?

   A. RL.
   B. RLC underdamped.
   C. RLC overdamped.
   D. RLC critically damped.

6. An SCR has half cycle surge current rating of 3000 A for 50 Hz supply. One cycle surge current will be_____?

   A. 1500 A.
   B. 6000 A.
   C. 2121.32 A.
   D. 4242.64 A.

7. 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

8. A string of n parallel SCRs is operated at 72 KA, the rating of each SCR is 1 KA. If derating factor of the string is 0.1. value of n will be___________?

   A. 60
   B. 70
   C. 80
   D. 90

9. If the gate voltage of an SCR is removed, then the_______________?

   A. anode current decreases
   B. anode current does not decrease at all
   C. anode current increases
   D. cathode current increases

10. The curve between V and I of SCR when anode is positive w.r.t cathode and when anode is negative w.r.t cathode are known as_____________________?

    A. both as forward characteristics
    B. both as reverse characteristics
    C. former as forward characteristics and later as reverse characteristics
    D. former as reverse characteristics and later as forward characteristics