In rectifiers, load current flow is_________?

Related Mcqs:

1. 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

2. 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°.

3. 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.

4. 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

5. The input current waveform of a bridge controlled rectifier when the load is perfectly filtered is___________?

   A. Sine wave
   B. Square wave
   C. Saw – tooth wave
   D. Trapezoidal wave

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. 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.

8. If the anode current is 800 A, then the amount of current required to turn off the GTO is about____________?

   A. 20 A
   B. 200 A
   C. 600 A
   D. 400 A

9. The reverse recovery time of diode is trr = 3 μs and the rate off all of the diode current is di/dt = 30 A/μs. The storage charge current QRR is___________?

   A. 130 μs
   B. 135 μs
   C. 140 μs
   D. 145 μs

10. 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