Initially,a rectangular coil with its length | vedclass

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(B) The induced e.m.f. in a conductor moving in a magnetic field is given by $\varepsilon = B l v \sin 	heta$,where $l$ is the length of the conducto

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less than the initial induced e.m.f.

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(B) The induced e.m.f. in a conductor moving in a magnetic field is given by $\varepsilon = B l v \sin 	heta$,where $l$ is the length of the conductor perpendicular to the velocity vector $v$ and the magnetic field $B$.In the initial case,the length of the coil is vertical,so the vertical side of length $L$ is perpendicular to the velocity $v$ (which is horizontal). Thus,the induced e.m.f. is $\varepsilon_1 = B L v$.After rotating the coil by $90^{\circ}$,the length $L$ becomes horizontal (parallel to the velocity $v$). The side that was previously horizontal (width $W$) is now vertical. The induced e.m.f. is now determined by the side perpendicular to the velocity,which is the side of length $W$. Thus,$\varepsilon_2 = B W v$.Since the length $L$ of a rectangular coil is typically greater than its width $W$ $(L > W)$,the new induced e.m.f. $\varepsilon_2$ will be less than the initial induced e.m.f. $\varepsilon_1$.

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