Electrical Engineering XYZ MCQs
Plug setting of a relay can be altered by varying:
- Adjustable back up stop
- Air gap of magnetic path
- No. of ampere-turns
- None of these
Correct answer: 3. No. of ampere-turns
Explanation: In electrical power systems, relays are used to protect equipment from damage caused by faults or abnormal conditions. One critical parameter in relay operation is the plug setting, which determines the threshold at which the relay should operate. The plug setting is typically expressed in terms of a certain multiple of the nominal current flowing through the protected equipment.
The plug setting of a relay can be altered by varying the number of ampere-turns in the relay’s operating coil. Ampere-turns represent the product of the number of turns in the coil and the current flowing through it. By adjusting either the number of turns or the current, the ampere-turns can be changed, thereby altering the relay’s plug setting.