Two identical loops, one of copper and the other of aluminium, are rot

1.	Two identical loops, one of copper and the other of aluminium, are rotated with the same angular speed in the same magnetic field. Compare(i) The induced emf and (ii) The current produced in the two coils. Justify your answer.
Answer» (i) Induced emf, ε = - \(\frac{dφ}{dt}\) = -\(\frac{d}{dt}\) (BA cos ωt) = BA ω sin ωt As B, A, ω are same for both loops, so induced emf is same in both loops. (ii) Current induced, I = \(\frac{ε}{R}\) = \(\frac{ε}{pl/A}\) = \(\frac{εA}{pl}\) As area A, length l and emf ε are same for both loops but resistivity ρ is less for copper, therefore current I induced is larger in copper loop.

Two identical loops, one of copper and the other of aluminium, are rotated with the same angular speed in the same magnetic field. Compare(i) The induced emf and (ii) The current produced in the two coils. Justify your answer.

Answer»

(i) Induced emf, ε = - \(\frac{dφ}{dt}\) = -\(\frac{d}{dt}\) (BA cos ωt)

= BA ω sin ωt

As B, A, ω are same for both loops, so induced emf is same in both loops.

(ii) Current induced, I = \(\frac{ε}{R}\) = \(\frac{ε}{pl/A}\) = \(\frac{εA}{pl}\)

As area A, length l and emf ε are same for both loops but resistivity ρ is less for copper, therefore current I induced is larger in copper loop.

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Two identical loops, one of copper and the other of aluminium, are rotated with the same angular speed in the same magnetic field. Compare(i) The induced emf and (ii) The current produced in the two coils. Justify your answer.

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