Electric Bell
Key Notes :
1. What is an Electric Bell?
- An electric bell is a device that produces a sound when an electric current passes through it.
- It is commonly used in schools, offices, and homes to signal or alert someone.
2. Components of an Electric Bell
- Electromagnet: A coil of wire wound around a metal core that becomes magnetic when electric current passes through it.
- Hammer: A small piece of metal that strikes the bell.
- Bell: The part that makes a ringing sound when struck by the hammer.
- Spring: A spring to return the hammer to its original position after striking the bell.
- Battery: Provides the electrical energy needed for the bell to function.
- Switch: Turns the circuit on and off, controlling the flow of electricity.
3. Working Principle
- When the switch is closed, the electric current flows through the coil of wire, making the electromagnet.
- The electromagnet attracts the hammer towards the bell, causing it to strike the bell and produce sound.
- The hammer is then pushed back by the spring to its original position, and the process repeats as long as the circuit is closed, creating a ringing sound.
4. Types of Electric Bells
- Simple Electric Bell: Operates using the basic principle mentioned above.
- Continuous Electric Bell: When the circuit is continuously closed, it keeps ringing without stopping until the switch is turned off.
5. Applications
- Schools: To signal the start or end of classes.
- Offices: To alert staff about important matters.
- Doorbells: Used at entrances to alert people of visitors.
6. Safety Precautions
- Make sure the electric bell is properly insulated to prevent electric shocks.
- Ensure the battery or power supply is installed correctly.
- Check for damaged wires and avoid overloading the circuit.
7. Important Terms
- Electromagnet: A magnet created by an electric current.
- Circuit: A complete path through which electric current flows.
- Conductor: A material that allows electric current to flow (e.g., copper wire).
Let’s practice!
