High Voltage Engineering MCQs Multiple Choice Questions Part 4

High Voltage Engineering MCQs

1. The relative dielectric strength of SF6 as compared to air is:
   1. 1.5 times
   2. 2 times
   3. 2.5 times
   4. 3 times

Ans: 3

2. The correct statement about Paschen’s law states that breakdown voltage of a uniform gap is directly proportional to:

1. 1. Pressure of the gas
   2. Separation of electrode
   3. Material of electrode
   4. All of these
   5. 1 & 3

Ans: 4

3. For determining intrinsic strength of dielectric the applied voltage should be of the order of:

1. 1. 10^-8 sec
   2. 10^-16 sec
   3. 10^-24 sec
   4. 10^-32 sec

Ans: 1

4. The ratio of voltage drop in a 6 stage to 3 stage Cockroft Walton circuit is:

1. 1. 6
   2. 2
   3. 9
   4. 1

5. Sometimes a void appears in the dielectric, the correct statement regarding the void is that its:

1. 1. 1. Electric field strength is lower than that of the dielectric
      2. Electric field strength is higher than that of the dielectric
      3. Electric field strength is exactly similar to the dielectric

Ans: 2

6. The onset voltage for Trichel pulses:

1. 1. Increases exponentially with increase in gap length
   2. Increases exponentially with decrease in gap length
   3. Increases directly with increase in gap length
   4. Is independent of gap length

Ans: 4

7. The frequency response of Rogowski coil is flat upto:

1. 1. 100 MHz
   2. 200 MHz
   3. 500 MHz
   4. 1000 MHz

Ans: 1

8. The small load current in Cockroft – Walton circuit means:

1. 1. Voltage drop is very large
   2. Voltage drop is small
   3. None of these
   4. Can’t predict

Ans: 2

9. The dielectric strength of liquids is of the order:

1. 1. 100 kV/cm
   2. 1000 kV/cm
   3. 5000 kV/cm
   4. 10000 kV/cm

Ans: 1

10. Temperature limit for Class H insulation is:

1. 1. 90°C
   2. 180°C
   3. 200°C
   4. 400°C

Ans: 2