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A magnet is brought closer to a coil in two ways: (i) rapidly and (ii) gradually. The induced e.m.f. in the coil will be
- greater in case (i)
- smaller in case (i)
- the same in both cases
- greater or smaller depending on the coil’s radius
Correct answer: greater in case (i)
Solution
Induced emf = -d(flux)/dt, so a faster (more rapid) approach produces a greater emf. Hence it is greater in case (i).
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