Select the correct sequence of the following actions that happen when the iron strip in the bell moves towards the electromagnet as shown in the figure below.

I. The electromagnet demagnetises.
II. The iron strip moves back to its original position.
III. The electric circuit breaks.

Electric bell works on the principle of electromagnetism.
 

It consists of an electromagnet, switch, iron strip, contact screw, hammer and a gong.

• When the switch is ON, the circuit gets closed and an electric current is passed through the circuit.
• Due to the electric current, the coil of iron starts acting as an electromagnet.
• This electromagnet pulls the iron strip.
•  In the process, the hammer at the end of the strip strikes the gong of the bell to produce a sound.
• When the electromagnet pulls the iron strip, the electric circuit breaks.
• Due to this, the electromagnet demagnetises and therefore, no longer attracts the iron strip.
• The iron strip then moves back to its original position.

Therefore, the correct sequence is III - I - II.