Answer: volt-second per ampere.
- A volt-second per ampere
- B ampere per second
- C volt per ampere
- D weber per second
Correct answer: A. volt-second per ampere
Explanation: From ε = −L dI/dt, 1 H = 1 V·s/A.
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.