Answer: Magnetic flux linked with the coil.
- A Resistance of the coil
- B Number of free electrons in the coil
- C Magnetic flux linked with the coil
- D Temperature of the coil
Correct answer: C. Magnetic flux linked with the coil
Explanation: According to Faraday's law, an EMF is induced in a coil only when the magnetic flux linked with it changes with time.
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.