Answer: bulk conductors.
- A bulk conductors
- B good insulators
- C a vacuum
- D gases only
Correct answer: A. bulk conductors
Explanation: A changing flux through a solid conductor sets up swirling eddy currents within it.
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.