Answer: BLv.
- A BL/v
- B BLv
- C BL<sup>2</sup> v
- D BL v<sup>2</sup>
Correct answer: B. BLv
Explanation: Motional EMF = BLv (rod moving perpendicular to both L and B). This is called motional EMF.
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.