A squre loop of side a= 12 cm with its sides parallel to x, and y-axis is moved with velocity, V=8 cm/s in the positive x direction in a magnetic field along the positive z-direction. The field is neither uniform in space nor constant in time. It has a gradient `delB//delx=-10^(-3) T//cm` along the x-direction, and it is changing in time at the rate `delB//delt=7T//sec` in the loop if its resistance is R`=4.5 Omega`. Find the current .

Answer

A, B, D

Explanation

`I=(EMF)/R=-(a^(2)deltaB)/(RdeltaX)v-(a^(2)deltaB)/(Rdeltat)=22.4mA`
Method II: Take `B=-10^(-3)x+7t+B_(0)` where `B_(0)` is constant
`phi=underset(y=x)overset(x+a)intadyB, epsilon=|(ddelta)/(dt)|,i=epsilon/R`