Answer: Induces EMF in a neighboring coil.
- A Changes resistance in another coil
- B Induces EMF in a neighboring coil
- C Changes voltage in same coil
- D Produces magnetic monopoles
Correct answer: B. Induces EMF in a neighboring coil
Explanation: Mutual inductance M: changing current in one coil induces EMF in a nearby coil. M = phi_21/I<sub>1</sub>.
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.