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What is meant by alternating current ? Derive the expression for a sinusoidal e.m.f. induced in a coil rotating with uniform angular speed in a uniform magnetic field. |
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Answer» Solution :Current that changes in its direction once in every half cycle is called as alternating currect. Let Magnetic FLUX, `PHI =BAN cos omega t` `e=(-dPhi)/(dt)` `e=BAN omega SIN omega t`. i.e., `e=e_0 sin omega t , e/R=(e_0)/R sin omega t, i=i_0 sin omegat` The direction of .e. is`+ve for Phi =0^@ "to" 180^@ ` and the induced current flows from X to Y and for `Phi =180^@ "to" 360^@` , the induced current flows from Y to X.  `e_(rms)=(e_(PEAK))/sqrt(2)` where `""e_(peak)=e_0=BAN omega` B - Magnetic flux density, A- Area of the conductor, N - No. of turns. `omega` - Angular frequency of rotation. |
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