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A coil of area `500cm^(2)` and having `1000` turns is held perpendicular to a uniform field of `0.4` gauss. The coil is turned through `180^(@)` in `1//10sec` . Calculate the average induced e.m.f.A. 0.02 VB. 0.04 VC. 1.4 VD. 0.08 V |
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Answer» Correct Answer - B Here, `A=500cm^(2)=500xx10^(-4)m^(2)` `N=1000,B=0.4G=0.4xx10^(-4)T` `t=(1)/(10)s` When the coil is held perpendicular to the field, the normal to the plane of the coil makes an angle of `0^(@)` with the field B. `:.` initial flux, `phi_(1)=BAcos0^(@)=BA` final flux, `phi_(2)=BAcos180^(@)=-BA` Average induced emf, `epsi=-N((phi_(2)-phi_(1))/(t))=-N((-BA-BA)/(t))` `=(2NBA)/(t)=(2xx1000xx0.4xx10^(-4)xx500xx10^(-4))/(1//10)=0.04V` |
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