When a fuse is rated 8 A, it means:

Options

A. it will not work if current is less - than 8 A
B. it has a resistance of 8 `Omega`
C. it will work only if current is 8 A
D. it will melt if current exceeds 8 A

Answer

**Step-by-Step Solution:**

1. **Understanding Fuse Rating**: A fuse is an electrical device that protects circuits from excessive current. The rating of a fuse, such as 8 A (amperes), indicates the maximum current that can safely pass through it.

2. **Current Threshold**: When a fuse is rated at 8 A, it means that it will allow current to flow through it as long as the current does not exceed 8 A. If the current is less than 8 A, the fuse will function normally and will not blow.

3. **Melting Point**: If the current flowing through the fuse exceeds 8 A, the fuse wire will heat up due to the increased current. This heating can cause the wire to melt, effectively breaking the circuit and stopping the flow of electricity. This is the protective function of the fuse.

4. **Resistance of the Fuse**: The fuse has a certain resistance, which can be approximated as 8 ohms (Ω). This resistance contributes to the heating effect when current flows through the fuse.

5. **Conclusion**: Therefore, when a fuse is rated at 8 A, it means that it is designed to protect electrical appliances by breaking the circuit if the current exceeds 8 A, preventing potential damage.

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