Answer: mutual induction.
- A mutual induction
- B self-conduction
- C electrostatic force
- D simple resistance
Correct answer: A. mutual induction
Explanation: A transformer transfers energy between coils by mutual induction.
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.