High Voltage Engineering MCQs
- The relative dielectric strength of SF6 as compared to air is:
- 1.5 times
- 2 times
- 2.5 times
- 3 times
Ans: 3
2. The correct statement about Paschen’s law states that breakdown voltage of a uniform gap is directly proportional to:
-
- Pressure of the gas
- Separation of electrode
- Material of electrode
- All of these
- 1 & 3
Ans: 4
3. For determining intrinsic strength of dielectric the applied voltage should be of the order of:
-
- 10-8 sec
- 10-16 sec
- 10-24 sec
- 10-32 sec
Ans: 1
4. The ratio of voltage drop in a 6 stage to 3 stage Cockroft Walton circuit is:
-
- 6
- 2
- 9
- 1
5. Sometimes a void appears in the dielectric, the correct statement regarding the void is that its:
-
-
- Electric field strength is lower than that of the dielectric
- Electric field strength is higher than that of the dielectric
- Electric field strength is exactly similar to the dielectric
-
Ans: 2
6. The onset voltage for Trichel pulses:
-
- Increases exponentially with increase in gap length
- Increases exponentially with decrease in gap length
- Increases directly with increase in gap length
- Is independent of gap length
Ans: 4
7. The frequency response of Rogowski coil is flat upto:
-
- 100 MHz
- 200 MHz
- 500 MHz
- 1000 MHz
Ans: 1
8. The small load current in Cockroft – Walton circuit means:
-
- Voltage drop is very large
- Voltage drop is small
- None of these
- Can’t predict
Ans: 2
9. The dielectric strength of liquids is of the order:
-
- 100 kV/cm
- 1000 kV/cm
- 5000 kV/cm
- 10000 kV/cm
Ans: 1
10. Temperature limit for Class H insulation is:
-
- 90°C
- 180°C
- 200°C
- 400°C
Ans: 2