Faraday's law: induced emf
A magnet is pushed into a coil of wire, inducing a current. Which change would produce a larger induced emf?
Answer A: explanation for every choice
A
Correct. Induced emf equals the rate of change of magnetic flux, so a faster change gives a larger emf.
B
A stationary magnet produces no change in flux, so no emf is induced.
C
Emf is proportional to the number of turns, so fewer loops lowers it.
D
A weaker magnet produces a smaller change in flux.
TakeawayFaraday's law: emf = −N ΔΦ/Δt.
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Reviewed 2026-11-05 by a medical student. Spot an error? Report it with question ID cp83.