When the electric bell collides with its gong due to electromagnetic force why it doesn't stick to it?instead it moves away and strikes again ?Why doesn't it stick to it due to the electromagnetic force and if the power supplied is low and due to that electromagnetic force is low that time.Why it is attracted to gong of bell and collides to it.

Asked by Sudha925 | 9th Dec, 2020, 10:26: AM

Expert Answer:

The soft iron bar acquires the magnetic properties only when an electric current flows through the solenoid and loses the magnetic properties as the current is switched off. That's why soft iron is used as the core of the electromagnet in an electric bell. When we press the switch the key/switch inside the circuit is closed and thus it complete the circuit and current flow in the electric circuir of bell. And if the switch is not pressed then switch in the circuit is open and thus current do not flow through the circuit as the circuit is incomplete. Thus, the armature returns to its position and thus the ringing of bell stop at that instant and do not continue ringing. 

Answered by Shiwani Sawant | 9th Dec, 2020, 09:05: PM