Electro Magnetic Induction And Alternating Currents Question 497
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 to the coil, it stops. This is due to:
Options:
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.
Show Answer
Answer:
Correct Answer: D
Solution:
- Because of the Lenz’s law of conservation of energy.
