A metallic bob A oscillates through the space between the poles of an electromagnet (figure). The oscillations are more quickly damped when the circuit is on, as compared to the case when the circuit is off. Explain.

Question

Philoid · Accepted Answer

When the circuit is on, eddy currents will produce on the surface of the metallic Bob. Eddy currents will generate thermal energy. Thermal energy comes as the loss of the kinetic energy of the Bob. Therefore, oscillations are more quickly damped when the circuit is on compared to when the circuit is of the bob.

Hence, oscillation is more quickly damped when the circuit is on compared to when the circuit is off.