What is the name of a safety device which cuts off the electricity supply during a short circuit by turning off a switch ?

Answer

**Step-by-Step Solution:**

1. **Understanding the Problem**: The question asks for the name of a safety device that cuts off the electricity supply during a short circuit by turning off a switch.

2. **Identifying the Device**: The device that performs this function is known as a Miniature Circuit Breaker (MCB).

3. **Function of MCB**: The MCB automatically shuts off the electricity supply when it detects a short circuit. Unlike a fuse, which melts and needs to be replaced, the MCB can be reset.

4. **Comparison with Fuse**: In a traditional electric fuse, when a short circuit occurs, the current increases, causing the fuse wire to melt and break the circuit. This requires the fuse to be replaced after it has blown.

5. **Resetting the MCB**: After a short circuit, to restore the electricity supply, one simply needs to switch the MCB back on. This allows the circuit to function normally again without the need for replacement.

6. **Conclusion**: Therefore, the safety device that cuts off the electricity supply during a short circuit is called a Miniature Circuit Breaker (MCB).

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