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Grade upto college level Magnetism

A rectangular coil of single turn, having area A, rotates in a uniform magnetic field B an angular velocity w about an axis is perpendicular to the field .If initially the plane of coil is perpendicular to the field,then the average induced e.m.f. when it has rotated through 90 degree is???a. wBA/pie b. wBA/2 pie c. wBA/4 pie d. 2wBA/ pie

Profile image of Kevin Nash
12 Years agoGrade upto college level
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1 Answer

Profile image of ROSHAN MUJEEB
6 Years ago
initially flux,ϕ=BAcos0=BA
After rotating through an angle90o.
Flux through the coil is zero.
So,Δϕ=BA

Angular speed=w, so, time period=ω/2π​=T

4T​is time taken to rotate90o.

So,ΔtΔϕ​=T/4BA​=π2BAω​