Answer: Opposes the change in magnetic flux that produced it.
- A Opposes the change in magnetic flux that produced it
- B Flows from north to south through the circuit
- C Aids the change in magnetic flux that produced it
- D Has no fixed relation to the change in magnetic flux
Correct answer: A. Opposes the change in magnetic flux that produced it
Explanation: Lenz's law states that the induced current flows in a direction that opposes the change in magnetic flux causing it, consistent with the conservation of energy.
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.