Question

Draw a neat and labelled diagram of an electric bell and also describe it’s working.
$\left[7\text{marks}\right]$

Answer 1

$\left[3\text{marks}\right]$

Working of the bell— Principle of working of electromagnetism when the switch is pushed on, the circuit gets completed and current stalls flowing through the U-shaped electromagnet which creates a magnetic field in the core. This attracts the iron armature. Now when the armature moves towards the electro-magnet, the hammer strikes the gong and the bell rings. But as the armature moves towards the electromagnet, the contact with the adjustment screw breaks which breaks the closed circuit and stops the current. Now when there is no current there is no electromagnetism and the armature returns to the original position. This making and breaking of the circuit of the electromagnet continues as long as the button remains pressed.
$\left[4\text{marks}\right]$