explain the working of an electric bell with the help of the above diagram for 8 marks and for 7th standard
Answers
Answer:
An electric bell contains an electromagnet, consisting of coils of insulated wire wound round iron rods. When an electric current flows through the coils, the rods become magnetic and attract a piece of iron attached to a clapper. The clapper hits the bell and makes it...
Answer:
the armature is fixed to the metallic springy strip.the hammer is attached at the end of the armature.tje metallic springy strip remains in contact with the adjusting screw when the switch is not pressed.
Explanation:
Initially when the switch is not pressed , no current flows in the coil of electromagnet .the metallic springy strip remains in contact with the adjusting screw.when switch is pressed,current flows through the coil.The metal becomes electromagnet .attracts the armature.the hammer strikes the gong due to the movement of armature. at the same time the contact between the springy strip and the armature does not remains.so circuit breaks.the armature returns to original place.as it gets contact with the springy strip circuit completes.magnet again attracts armature.hits the gong.this goes on as the switch is pressed and electricity passes through the coil