# High Voltage Engineering MCQs Part 6

1. The dielectric strength of air is approx:
1. 10 kV/in
2. 20 kV/in
3. 200 kV/in
4. 5000 kV/in
• Correct answer: b. 20 kV/in
2. ____________ is/are expected to have treeing phenomenon:
1. Capacitors
2. Cables
3. Dielectrics
4. All of these
• Correct answer: 4. All of these
3. Chubb–Fortescue method of measurement of a.c peak voltage values contains:
1. A capacitor, two diodes, an ammeter, a Resistor and an overvoltage protector
2. An inductor, two diodes, an ammeter, a Resistor and an overvoltage protector
3. A capacitor, one diode, a voltmeter, a Resistor and an overvoltage protector
4. An inductor, two diodes, a voltmeter, a Resistor and an overvoltage protector
• Correct answer: A capacitor, two diodes, an ammeter, a Resistor and an overvoltage protector
4. Capacitor bushing use _______________ type of paper:
1. Oil impregnated paper
2. Resin bonded paper
3. Resin impregnated paper
4. All of these
• Correct answer: 4. All of these
5. The radial stress of resin bonded paper capacitor busing is:
1. 10 kV/cm
2. 20 kV/cm
3. 30 kV/cm
4. 40 kV/cm
• Correct answer: 2. 20 kV/cm
6. The long-term breakdown is also known as:
1. Ageing breakdown
2. Menacing breakdown
3. Both of these
4. None of these
• Correct answer: 1. Ageing breakdown
7. __________________ considers the dependence of breakdown strength of liquid on length of gap:
1. Suspended particle theory
2. Bubble theory
3. Stressed oil volume theory
4. None of these
• Correct answer: 4. None of these
8. Experiments suggest that breakdown strength of liquids depends primarily on:
1. Length of gap
2. Hydrostatic pressure
3. Impurity particles
• Correct answer: 1. Length of gap
9. Paschen law relates the breakdown voltage with pressure and electrode separation. For a particular gas the correct relationship as per Paschen’s law is:
1. Breakdown voltage is directly proportional to pressure and inversely to separation
2. Breakdown voltage is directly proportional to separation and inversely to pressure
3. Breakdown voltage is inversely proportional to both
4. Breakdown voltage is directly proportional to both
• Correct answer: 4. Breakdown voltage is directly proportional to both
10. The cable routine test involves the application of ac voltage which is ________ times rated rated voltage and for approximately _______ minutes:
1. 1/2, 2 minutes
2. 1.5, 3 minutes
3. 2.5, 10 minute
4. 10, 50 minute
• Correct answer: 2.5, 10 minute