Answer: voltage.
- A voltage
- B current
- C frequency
- D total power
Correct answer: A. voltage
Explanation: A step-up transformer raises voltage (while lowering current, conserving power).
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.