Question

Explain the construction and working of electric bell with figure.

Answer 1

The electric bell works on the principle of the electromagnet. Its construction is shown in the above figure.

Construction: It is made of an electromagnet, bell(metallic cup), soft iron strip(which works as a hammer) and contact screw. The bell is a cup-shaped device made of metal. A soft iron strip works as a small hammer.

Working: When current is passed through the circuit, the electromagnet acts like a magnet and attracts the iron strip. The iron strip(hammer), being elastic, strikes the bell. Simultaneously, its contact with the screw is broken, the circuit breaks and the current stops flowing through the electromagnet. As such, the iron strip returns to its original position, and again the current passes through the electromagnet.

This phenomenon happens many times in a second, and as the hammer strikes the bell, the sound is heard. The bell rings till the circuit has been switched off. The electric bell is used in alarms and bells is schools, offices, homes and industries.