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Question
A rectangular coil of area A, having the number of turns N is rotated at 'f' revolutions per second in a uniform magnetic field B, the field being perpendicular to the coil. Prove that the maximum emf induced in the coil is 2 πf NBA.
Solution
We know that flux is given by
`phi=NBACostheta`
we also know,
`e=-(dphi)/dt=(-NBA(-sintheta)(d theta)/dt)`
`=NBAsin theta(2pif)`
For maximum induced emf = sinθ = 1
`e_max=(-NBAsin theta (d theta)/dt)`
`=NBA(2pif)`
Hence proved.
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