Electrical Engineering XYZ MCQs
Mho relay is usually employed for protection of:
- Medium transmission lines only
- Short transmission lines only
- Long transmission lines only
- All of above
Correct answer: 3. Long transmission lines only
Explanation: The Mho relay, also known as the impedance relay, is typically employed for the protection of long transmission lines. Mho relays operate based on the impedance measurement of the line and are commonly used for transmission lines because they offer advantages in terms of sensitivity and selectivity.
Here’s a brief explanation of the options:
- Medium transmission lines only: While Mho relays can be used for medium transmission lines, they are more commonly associated with long transmission lines.
- Short transmission lines only: Mho relays are not typically used for short transmission lines. Short lines are usually protected by distance relays or overcurrent relays.
- Long transmission lines only: This is the correct answer. Mho relays are well-suited for the protection of long transmission lines due to their ability to measure impedance and provide selective and sensitive protection.
- All of above: While Mho relays can be used for medium and long transmission lines, they are not commonly used for short transmission lines. Therefore, the statement “All of above” is not entirely accurate.