A coil is suspended in a uniform magnetic field, with the plane of the coil parallel to the magnetic lines of force.
A coil is suspended in a uniform magnetic field, with the plane of the coil parallel to the magnetic lines of force. When a current is passed through the coil it starts oscillating; it is very difficult to stop. But if an aluminium plate is placed near to the coil, it stops. This is due to
(a) induction of electrical charge on the plate.
(b) shielding of magnetic lines of force as aluminium is a paramagnetic material.
(c) electromagnetic induction in the aluminium plate giving rise to electromagnetic damping.
(d) development of air current when the plate is placed.
2 Answers
(c) electromagnetic induction in the aluminium plate giving rise to electromagnetic damping.
Correct Option(c) electromagnetic induction in the aluminium plate giving rise to electromagnetic damping.
Explanation:
According to Lenz,s law, electromagnetic induction takes place in the aluminium plate due to which eddy current is developed which oppose the motion or vibrations of the coil.
This causes loss in energy which results in damping of oscillatory motion of the coil.