Question

How is the working of electric bell effected if ac current is used instead of dc current?

Answer 1

Dear Student,

AC and DC based bells are different. In case of a DC based bell an electric current is passed through the winding of the electromagnet and it creates a magnetic field that attracts the iron arm of the clapper, pulling it over to give the bell a tap. This opens a pair of electrical contacts attached to the clapper arm, interrupting the current to the electromagnet. The magnetic field of the electromagnet collapses, and the clapper springs gets away from the bell. This closes the contacts again, allowing the current to flow to the electromagnet again, so the magnet pulls the clapper over to strike the bell again. This cycle repeats rapidly many times per second, resulting in a continuous ringing.In case of the AC based bell the ringing is produced due to continues change in the polarity of the voltage (sinusoidal voltage). Therefore, AC supply cannot be used for the DC based electric bell.

Regards