Question:
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 the coil, it stops. This is due to
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 the coil, it stops. This is due to
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Eddy currents always oppose the motion that produces them, leading to magnetic damping.
Updated On: Mar 19, 2026
- development of eddy current when the plate is placed
- induction of electrical charge on the plate
- shielding of magnetic lines of force
- aluminium is a paramagnetic material
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The Correct Option is A
Solution and Explanation
Step 1: When the coil oscillates near the aluminium plate, the magnetic flux linked with the plate changes.
Step 2: Changing magnetic flux induces eddy currents in the aluminium plate.
Step 3: According to Lenz’s law, these eddy currents oppose the motion of the coil.
Step 4: The opposing force causes electromagnetic damping, stopping the oscillations.
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