Question

A wire of length `l` in the from of a circular loop lies in a plane normal to a magnetic firld `B_(0)` . If this wire is converted into a square loop in time `t_(0)` , find the average induced emf.

Answer 1

`t=2pir implies r=(t)/(2pi)`
Side of square `L=(t)/(4)`
`Iphi_(I)=Bpir^(2)=(Bpit^(2))/(4pi^(2))=(Bt^(2))/(4pi)`
`phi_(2)=BL^(2)=( Bt^(2))/(I6)`
`bar(e)=-(phi_(2)-phi_(I))/(Deltat)=-(Bt^(2))/(t_(0))((I)/(I6)-(I)/(4pi))`
`=(Bt^(2))/(I6pit_(0))(4-pi)`