Answer: greater.
- A greater
- B smaller
- C zero
- D unchanged
Correct answer: A. greater
Explanation: Induced EMF is proportional to the rate of change of flux, so a faster change gives a larger EMF.
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.