Answer: Ns/Np.
- A Ns/Np
- B Np/Ns
- C the product Ns·Np
- D the difference Ns − Np
Correct answer: A. Ns/Np
Explanation: Vs/Vp = Ns/Np, the ratio of the numbers of turns.
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.