Assertion (A): If a cylindrical bar magnet is dropped through a metallic pipe, it takes more time to come down a similar unmagnetised cylindrical iron bar dropped through the same metallic pipe.
Reason (R): For the magnet, eddy currents are produced in the metallic pipe.
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false
Solution:
As the magnet falls, changing flux induces eddy currents in the pipe. These currents oppose the magnet's motion (Lenz's Law), creating a retarding force that slows it down.
Leave a Reply