Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: A bar magnet dropped through a metallic cylindrical pipe takes more time to come down compared to a non-magnetic bar with same geometry and mass.
Reason R: For the magnetic bar, Eddy currents are produced in the metallic pipe which oppose the motion of the magnetic bar.
In the light of the above statements, choose the correct answer from the options given below
Assertion A: A bar magnet dropped through a metallic cylindrical pipe takes more time to come down compared to a non-magnetic bar with same geometry and mass.
Reason R: For the magnetic bar, Eddy currents are produced in the metallic pipe which oppose the motion of the magnetic bar.
In the light of the above statements, choose the correct answer from the options given below
- (A)Both and are true but is NOT the correct explanation of
- (B) is true but is false
- (C)Both and are true and is the correct explanation of ✓ Correct
- (D) is false but is true
Answer: (C)
Solution
When a bar magnet falls through a metallic pipe, the changing magnetic flux induces eddy currents in the pipe. By Lenz's law, these eddy currents create a magnetic field that opposes the motion of the magnet, effectively retarding its fall. This causes the magnet to take more time to fall compared to a non-magnetic bar of the same mass and geometry. Both statements are true, and R correctly explains A.
JEE Main · 2023 · 11 Apr 2023 · Shift 2 · Single correct option