ON state voltage drop across SCR lie between the range_____________?

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. 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.

3. The on – state voltage drop of IGBT consists of__________?

   A. Drop across the collector junction
   B. Drop across the drift region
   C. Drop across MOSFET portion
   D. All of these

4. A thyristor string is made of a no. of SCR connected in series and parallel. The string have volume and current of 11 KV and 4 KA. The voltage and current rating of available SCRs are 1800 V and 1000 A. For a string efficiency of 90 % let the number of SCRs in series and parallel are a and b respectively. Then the value of a and b will be_____________?

   A. 5, 7
   B. 4, 6
   C. 7, 5
   D. 6, 4

5. 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

6. 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

7. In current commutated DC-DC choppers, the voltage spike appears across the load when_____________?

   A. Voltage across the commutating inductances collapses
   B. The capacitance voltage adds to the supply voltage
   C. Both A. and B.
   D. None of these

8. In a full bridge VSI, in order to avoid the short circuit across the DC bus and the undefined AC output voltage condition, the modulating technique should ensure that___________?

   A. Top switch of each leg is on at any instant
   B. Bottom switch of each leg is on at any instant
   C. Either A. or B.
   D. None of these

9. A step up chopper has input voltage 110 V and output voltage 150 V. The value of duty cycle is_____?

   A. 0.32
   B. 0.67
   C. 0.45
   D. 0.27

10. Under over voltage condition impedance offered by the voltage clamping device is__________?

    A. low
    B. High
    C. moderate
    D. infinity