Name: Magnets and Magnetism
Uploaded: 2019-07-19
Duration: 3 min 46 s
Description: In this video, we will learn about the different types of magnets and the magnetic field created by different types of magnets. Learn more.

Question

Demonstrate the working and construction of an electric bell with the help of a diagram.

Accepted Answer

An electric bell is an application of an electromagnet.

Construction: It consists of an electromagnet, contact spring, contact screw, armature, and a hammer and gong which is fitted on a flat wooden or plastic board.

Working: The terminals $T_{1}$ and $T_{2}$ of the bell are connected to a battery through a push-button switch. When the switch is ON, current flows from the battery to the electromagnet and then to the contact screw. From the contact screw, it flows to terminal $T_{2}$ and again to the battery. Thus, the electric circuit is completed.
As current flows through the U -shaped electromagnet, it gets magnetized and attracts the armature made of iron towards it. As a result, the hammer attached to the armature hits the gong, and a sound is produced.

Due to the displacement of the armature from its original position, it loses contact with the contact screw. This breaks the circuit and the current stops flowing through the electromagnet. Thus, the electromagnet loses its magnetism. The spring pulls the armature back to its original position. This once again completes the circuit and the electric current starts flowing. The whole sequence of the hammer hitting the gong is repeated as long as the push-button switch is kept pressed.

Demonstrate the working and construction of an electric bell with the help of a diagram.

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