Question

The bell shown in the picture works the same way that a doorbell works. The bell only rings when the electromagnet pushes on the beater bar. The magnetic force moves the beater bar so that it rings the bell.


Most of the time, the bell does not ring because the electromagnet is off. What turns the electromagnet on when a person pushes the doorbell button?
A.
the energy of the person's finger
B.
a build up of static charge
C.
a current in the coil of the electromagnet
D.
the movement of another magnet

Answer 1

C. A current in the coil of the electromagnet.

Pressing the doorbell button closes the electrical circuit so current flows from the power source through the coil. That current produces the magnetic field (electromagnet) which pulls the beater to ring the bell.