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Suppose a coil of area `5m^(2)`, resistance `10Omega` and number of turns 200 held perpendicular to a uniform magnetic field of strengh `0.4`T. The coil is now turned through `180^(@)` in time 1 s. What is (i) average induced emf (ii) average induced current (iii) total charge that flows through a given cross-setion of the coil? |
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Answer» Given, area of coil, `S=5m^(2)`, resistance, `R=10Omega`, number of turns, N = 200, magnetic field, B = `0.4T,Deltat=1s`. When the plane of coil is perpendicular to the magnetic field i.e.,`theta_(i)=0^(@)`. And after it is rotated through `180^(@)`, then `theta_(f)=180^(@)`. `rArr"Initial flux,"phi_(i)=NBS cos 0^(@)=NBS` `=200xx0.4xxs=400Wb` and final flux =NBS `cos 180^(@)=-NBS=-400Wb` `rArr"Change in flux",|Deltaphi_(B)|` `=NBS-(-NBS)=2NBS=800Wb` (i) Average induced emf `(epsilon)=(|Deltaphi|)/(Deltat)=(2NBA)/(Deltat)=800V` (ii) Average induced emf `=(epsilon)/(R)=(2NBA)/(Deltat)=80A` (iii) Average change `=(DeltaQ)/(Deltat)=(2NBA)/(RDeltat)` `rArr" Total charge "DeltaQ=(2NBA)/(R)=80C` |
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