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.
developement of air current when the plate is placed
B.
induction of electrical charge on the plate
C.
shielding of magnetic lines of force as aluminium is a paramagnetic material.
D.
electromagnetic induction in the aluminium plate giving rise to electromagnetic damping.
Answer :
electromagnetic induction in the aluminium plate giving rise to electromagnetic damping.
Solution :
Because of the Lenz's law of conservation of energy.
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