*Question T0A04:
What is the purpose of a fuse in an electrical circuit?*  

*Correct Answer is  B: To remove power in case of overload*  

### AI Response: (may contain errors)  

The correct answer to the question about the purpose of a fuse in an electrical circuit is:

**B: To remove power in case of overload.**

### Explanation of the Correct Answer:
- A fuse is a safety device designed to protect electrical circuits from excessive current. When the current exceeds a certain threshold, the fuse element melts, breaking the circuit and preventing further current flow. This helps to avoid overheating and potential fire hazards.

### Why the Other Choices are Incorrect:
- **A: To prevent power supply ripple from damaging a component**  
  - This is incorrect because a fuse does not filter or regulate voltage ripple. Instead, components like capacitors are used for that purpose.

- **C: To limit current to prevent shocks**  
  - While a fuse does interrupt current flow in case of overload, it does not actively limit current under normal operating conditions. Current limiting is typically achieved with devices like circuit breakers or current-limiting resistors.

- **D: All these choices are correct**  
  - Since choices A and C are incorrect, this option cannot be correct.

### Useful Rules of Thumb:
- Always select a fuse with a rating appropriate for the circuit it protects. The fuse rating should be slightly higher than the normal operating current but lower than the current that could cause damage.
- A common rule of thumb is to use a fuse rated for 125% of the continuous load current to ensure protection without nuisance blowing.

In summary, the primary function of a fuse is to remove power in case of overload, ensuring safety in electrical circuits.