Answer: Generator.
- A Motor
- B Transformer
- C Rectifier
- D Generator
Correct answer: D. Generator
Explanation: A generator uses electromagnetic induction, typically by rotating a coil in a magnetic field, to convert mechanical energy into electrical energy.
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.