Find the applied horizontal force on BC, (F) as a function of time `'t' (t < l/v)`A conducting square wire frame ABCD of side `l` is pulled by horizontal force so that it moves with constant velocity v. A uniform magnetic field of strength B is existing perpendicular to the plane of wire. The resistance per unit length of wire is `lambda` and negligible self inductance. If at `t= 0,` frame is just at the boundary of magnetic field.

Question

Find the applied horizontal force on BC, (F) as a function of time `'t' (t < l/v)`

A conducting square wire frame ABCD of side `l` is pulled by horizontal force so that it moves with constant velocity v. A uniform magnetic field of strength B is existing perpendicular to the plane of wire. The resistance per unit length of wire is `lambda` and negligible self inductance. If at `t= 0,` frame is just at the boundary of magnetic field. Then

Options:
(a) `(B^2vl)/lambda t` (b) `(B^2vl)/(2lambda)` (c) `(B^2vl)/(4lambda)` (d) None of these