To detect an over – current fault condition, the most reliable method is to connect a_____________?

Related Mcqs:

1. CB used for over current protection of thyristor operates when the fault current is__________?

   A. of long period
   B. of short duration
   C. both (A) and (B)
   D. neither (A) nor (B)

2. In a load commutated DC – DC chopper, the capacitor has a_____________?

   A. Symmetric triangular voltage across itself
   B. Symmetric rectangular voltage across itself
   C. Symmetric trapezoidal voltage across itself
   D. Symmetric sinusoidal voltage across itself

3. A crowbar is a circuit which is used to protect a_____________?

   A. voltage sensitive load from excessive dc power supply output voltages
   B. current sensitive load from excessive dc power supply output voltages
   C. voltage sensitive load from excessive ac power supply output voltages
   D. current sensitive load from excessive ac power supply output voltages

4. In a flyback converter, the inductor of the buck-boost converter has been replaced by a_____________?

   A. Flyback capacitor
   B. Flyback resistor
   C. Flyback transformer
   D. Flyback transistor

5. With gate open, the maximum anode current at which SCR is turned off from ON condition is called____________?

   A. breakdown voltage
   B. peak reverse voltage
   C. holding current
   D. latching current

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

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

7. Under normal operating condition voltage clamping device offers impedance of_________?

   A. high value.
   B. low value.
   C. zero value.
   D. moderate value.

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. 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

10. 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