Suppose a long rectangular loop of width w is moving along the x-direction with its left arm in a magnetic field perpendicular to the plane of the loop (see figure). The resistance of the loop is zero and it has an inductance L. At time t = 0, its left arm passes the origin O.

If for ` t ge 0` the current in the loop is I and the distance of its left are arm from the origin is x then I versus x graph will be

Options

A.
B.
C.
D.

Answer

B

Explanation

`VB -L ( di )/(d t) =0`
` VB l =L (di)/(dt) `
` implies (di )/(dt) = (VB l )/(L ) `
`= + ` ve slope
` x= ut implies(dx)/(dt) =V `
` (di )/( dx ) = (Bl )/(L ) = +` ve slope