A conducting square frame of side ‘a’ and along straight wire carrying current I are located in the same plane a shown in the figure. The fame moves to the right with constant velocity ‘v’. The emf induced in the frame will be proportional to:
1(2x−a)(2x+a)
¯B1=μ0I2π[x−a2]=μ0Iπ[2x−a]¯B2=μ0I2π[x+a2]=μ0Iπ[2x+a]emf=dϕdt=d(BA)dt(ϕ=BA)=AdBdt=a2[¯B1−¯B2]=a2[μ0Iπ[2x−a]−μ0Iπ[2x+a]]=μ0Iπa2[12x−a−12x+a]=μ0Iπa2[2x+a−(2x−a)(2x−a)(2x+a)]=μ0Iπa2[2a(2x−a)(2x+a)]