Answer: power.
- A power
- B charge
- C resistance
- D frequency
Correct answer: A. power
Explanation: With no losses, input power equals output power, giving VpIp = VsIs.
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.