Question

Explain the construction and working of an electric bell with the help of a neat and labeled diagram.

Answer 1

The construction of an electric bell consists of a gong , an electromagnet , a soft iron rod and a contact screw . The working of an electric bell : When the current passes through the electromagnet , it becomes magnetized which helps to attract the armature and after this the hammer raids and attract the armeture .

Answer 2

Electrical Bell

The electrical Bell works on the magnetic effect of current. It has an electromagnet in it.

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The electric bell has a 'U' shaped electromagnet. A small iron bar, called armature, is held in front of the poles. The lower end of the armature is attached to a flat spring and the spring is itself fixed to a metal bracket. The upper end of the armature has a hammer attached to it. There is a contact screw which just touches the armature at the point 'E'. A metal gong is fixed near the hammer. The Electromagnet is connected to a battery, puch button switch and the armature is in the circuit.

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The working of Electrical Bell is as follow

★ When we press the switch the electrical circuit of the bell is completed and the current passes through the coil of the electromagnet and it gets magnetised. The Electromagnet attracts the armature towards itself, the hammer attached to it strikes the gong and produce a sound.

★ When the armature moves towards the magnet it's contact with the contacts screw is broken at point 'E'. Due to this the electrical circuit breaks and no current flows in the electromagnetic coil. The Electromagnet loses its magnetism and armature is no longer attached by it. The spring brings back the armature to its original position and hammar moves away from the gong.

★ As soon as the armature comes back and touches contact screw, the current is complete and the current starts flowing in the electromagnetic coil again. The process of make and break of electric current occurs when we press. Thus, the hammer strikes on the gong rapidly and producing almost continuous sound and we say that the bell is ringing.