Answer: eddy currents.
- A eddy currents
- B friction alone
- C gravity
- D air resistance alone
Correct answer: A. eddy currents
Explanation: Induced eddy currents oppose the motion (Lenz’s law), damping the swing.
As a magnet approaches a coil, flux rises steadily and a constant non-zero EMF is induced (Faraday's law). Once the magnet stops moving, flux stays constant and the induced EMF drops to zero - EMF only exists while flux is actively changing.
Concept context
Faraday's and Lenz's laws, motional EMF, self/mutual inductance, eddy currents, and the AC generator - how a changing magnetic flux creates an electric current.