Power System MCQs Part 9
Power System MCQs Part 9
Contents
For reducing tower footing resistance it is better to employ
For reducing tower footing resistance it is better to employ
- Chemical and ground rods only
- Ground rod and counterpoise only
- Chemical and counterpoise only
- Chemical, ground rods and counterpoise
Correct answer: 2. Ground rod and counterpoise only
The size of conductor on modern EHV lines is obtained based on
The size of conductor on modern EHV lines is obtained based on:
- Voltage drop
- Current density
- Corona
- None of these
Correct answer: 3. Corona
Which of following is correct regarding a short length of cable between the dead end tower and the power transformer
Which of following is correct regarding a short length of cable between the dead end tower and the power transformer
- It reduces the steepness of the wave under certain conditions only
- It does not change the steepness
- It always reduces the steepness of the incident wave
Correct answer: 3. It always reduces the steepness of the incident wave
Minimum oil circuit breaker has less volume of oil because
Minimum oil circuit breaker has less volume of oil because
- There is insulation between contacts
- Solid insulation is provided for insulating the contacts from earth
- The oil between the breaker contacts has greater strength
- None of these
Correct answer: 2. Solid insulation is provided for insulating the contacts from the earth
If r is the radius of the conductor and R the radius of the sheath of the cable, the cable operates stably from the view point of dielectric strength if
If r is the radius of the conductor and R the radius of the sheath of the cable, the cable operates stably from the view point of dielectric strength if:
- r/R > 1.0
- r/R < 1.0
- r/R < 0.368
- r/R < 0.667
Correct answer: 3. r/R < 0.368