Question

From the following options find which is not a component of electric bell?
(a) Ferromagnetic strip
(b) Low magnetic field permanent magnet to attract ferromagnetic strip
(c) Gong
(d) Hammer

Answer 1

Hint: Working principle of electric bells is based on the principle of electromagnetism. To answer this we must know the name of parts which are used in electric bell i.e. Armature, Armature rod, Gong and Hammer, Ferromagnetic strip.

Complete step by step answer:
Electric bell is a basic circuit that triggers a sound on the termination of the circuit by pressing the button. We should first understand electromagnetism, to learn the working principle of electric bells. Electric bell is fundamentally a kind of magnet in which the magnetic field is created with the resistance of an electric flow . At the point when any electrical impacts electromagnet it functions as a standard magnet. In an electric bell there are no permanent magnets used in it; this is one type of temporary magnet. It works in such a manner – first we press the switch and current follows through the circuit which provides power to electromagnet . After that this electromagnet generates a magnetic field which attracts the ferromagnetic trip towards it . Then the striker strikes the Gong.
Therefore, we can say that option (b) is the right answer.

Note: In temporary magnets whenever current flow is stopped the iron strip returns back to its initial state. Electromagnets are used in telephones, washing machines, refrigerator, loudspeaker etc.