Answer: flux.
- A flux
- B charge
- C current
- D voltage
Correct answer: A. flux
Explanation: ε = −N dΦ/dt; the turns multiply the effect of the changing flux.
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.