The safety device based on the heating effect of electric current is called a fuse .

Fuse:
A fuse is a safety device that is used to protect electrical circuits from overloading and short circuits. It is a thin strip of metal or wire that is designed to melt and break the circuit when excessive current flows through it. Fuses are commonly used in electrical systems to prevent damage to appliances, equipment, and wiring.

Working of a Fuse:
When the current flowing through a circuit exceeds the rated capacity of the fuse, the fuse wire or strip heats up due to the resistance offered by it. As the temperature rises, the fuse wire or strip melts and breaks the circuit, interrupting the flow of current. This action protects the circuit from damage by preventing excessive current from flowing through it.

Types of Fuses:
1. Cartridge Fuses: These fuses consist of a cylindrical body and are available in various sizes. They are commonly used in household electrical systems and industrial applications.
2. Plug Fuses: These fuses are typically used in older homes and have a threaded base that can be screwed into a fuse socket.
3. Resettable Fuses: Also known as circuit breakers, these fuses automatically reset after the fault is cleared. They are commonly used in modern electrical systems.

Importance of Fuses:
Fuses play a crucial role in electrical safety. Here are some reasons why fuses are important:
- Prevents overloading: Fuses protect electrical circuits from excessive current that can damage appliances and equipment.
- Prevents short circuits: Fuses break the circuit when a short circuit occurs, preventing potential fires or electrical hazards.
- Easy to replace: Fuses are relatively inexpensive and easy to replace compared to repairing or replacing damaged equipment.
- Provides visual indication: In case of a blown fuse, the fuse wire or strip will melt, providing a visual indication that the circuit has been interrupted.

Conclusion:
Fuses are essential safety devices that protect electrical circuits from overloading and short circuits. They are designed to melt and break the circuit when excessive current flows through them. Fuses are available in different types and are widely used in households, industries, and electrical systems to ensure the safety of appliances, equipment, and wiring.