Question

Consider the following statements:

Sphere gap method of voltage measurement is used

1. for measuring r.m.s. value of a high voltage

2. for measuring peak value of a high voltage

3. as the standard for calibration purposes

Which of the above statements are correct?
1. 1 and 2 only
2. 2 and 3 only
3. 1 and 3 only
4. 1, 2 and 3

Answer 1

Correct Answer - Option 2 : 2 and 3 only

Sphere gap method of Voltage measurement: Measurement of the potential energy of an electric field to cause an electric current in an electrical conductor.

• Voltage is the difference in electrical potential between two points of an electrical or electronic circuit.
• A uniform field spark gap will always have a spark over voltage within a known tolerance under constant atmospheric pressure.
• Hence a spark gap can be used to measure the peak value of high voltage if the gap distance is known.
• Measurement is reliable only for certain gap configurations.
• It can be used for radio frequency a.c. voltage peak measurement also (up to 1 MHz)
• It is also used as the standard for calibration purposes.
• Calibration is the comparison of measured values with those of a calibration standard of known accuracy.