Answer: Is constant during entry, zero when fully inside.
- A Increases then stays constant under most conditions encountered
- B Is constant as frequently observed in practice
- C Decreases to zero when largely inside in many documented cases
- D Is constant during entry, zero when fully inside
Correct answer: D. Is constant during entry, zero when fully inside
Explanation: As coil enters: flux increases at constant rate (constant velocity), so constant EMF and constant current. When fully inside: no flux change, no current.
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.