Assertion (A): At the instant when magnetic flux is zero, emf induced in the coil is maximum when it is rotating in uniform magnetic field w.r.t. axis in the plane of coil.
Reason (R): emf induced in the coil is equal to rate of change of magnetic flux.
Both A & R are true and the (R) is the correct explanation of the (A)
Both A & R are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false
Solution:
Induced emf is \(E = -d\phi/dt = BA\omega sin(\omega t)\). Magnetic flux is \(\phi = BA cos(\omega t)\). When \(\phi = 0\), \(cos(\omega t) = 0\), which implies \(sin(\omega t) = 1\). Thus, \(E\) is maximum. Both A and R are true, and R correctly explains A.
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