Lenz's Law, Eddy Currents & Induced Electric Field
Given below are two statements: one is labelled as Assertion and the other is labelled as Reason
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
Show answer and solution
Answer: (d)
- A falling magnet changes the flux through the metal pipe, inducing eddy currents (R is true).
- By Lenz's law these currents oppose the magnet's motion, so it falls more slowly than a non-magnetic bar, which induces no currents (A is true).
- R directly explains A. So the answer is (d).