What is the name of a safety device which cuts off the electricity supply during a short circuit by breaking a thin wire ?

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of a safety device that interrupts the electricity supply during a short circuit by breaking a thin wire.

2. **Identifying the Device**: The device that performs this function is known as a "fuse."

3. **Function of a Fuse**: A fuse contains a thin wire that is designed to melt and break when the electric current exceeds a certain limit, which is known as the rated value of the fuse.

4. **Example of Operation**: For instance, if a fuse has a rated value of 5 amperes and a short circuit occurs, the current will exceed 5 amperes. This excess current causes the thin wire inside the fuse to heat up and eventually melt, breaking the circuit.

5. **Result of the Fuse Action**: When the wire breaks, the circuit is opened, effectively cutting off the electricity supply. This action protects the electrical devices and appliances connected to the circuit from damage.

6. **Replacement of the Fuse**: After a fuse has blown (the wire has melted), it must be replaced with a new fuse to restore the electrical supply.

**Final Answer**: The name of the safety device is a **Fuse**.

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