How electric bell works

An electric bell consists of an electromagnet, a switch ,an armature like structure that is held by a spring and make and break arrangement with screw and iron bar. When the switch is pressed, the circuit is closed the electric current starts flowing through the wire and coil of electomagnet. Then the electromagnet starts acting like a magnet and it attracts the iron bar towards itself and the hammer attached to the iron bar strikes the gong and the bell rang. When electomagnet attracts iron bar it loses it contact with the screw. When it loses it's contact ,the circuit is broken and current does not flow through it and electromagnet releases the iron bar. Now, when it is released, again it comes in contact with screw and the circuit is closed, now again electromagnet attracts iron bar towards itself . This work of making and breaking of circuit continues till the switch is pressed and the hammer strikes the gong.

Electric current flows through the coil when the switch is ON, and the iron core acts as an electromagnet. The iron core attracts the hammer towards it. The hammer hits the bell and produces a sound. The circuit breaks at the screw contact when the hammer moves towards the iron core. At this point, the iron core ceases to be an electromagnet. The hammer is pulled back to its original position due to the spring action of the steel rod, and then touches the contact again to complete the circuit. The circuit is completed and current flows through the coil again, and the hammer strikes the bell again. The process repeats itself and you hear a ringing sound since the hammer keeps hitting the bell, until the switch is released.