Answer: 1 V.
- A 1 mV
- B 1 V
- C 10 V
- D 100 V
Correct answer: B. 1 V
Explanation: EMF = -L x dI/dt = 100 x 10<sup>-3</sup> x 10 = 1 V.
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.