Two metal strips of length l each are placed parallel to each other in contact with an electric circuit as shown in Fig. 1.135. The entire structure is placed on a smooth horizontal floor in a region in which magnetic field is existing in vertical direction. The distance travelled by the wire as a function of time is best given by
where `t_0 = sqrt ((2lmR)/(EBb))`

Options

A. `1/2xx(EB b)/(Rm)xxt^2` for `tltt_0` and `(l+(EBb)/(Rm)(t-t_0))` for `tget_0`
B. `1/2xx(Eb b)/(Rm)xxt^2` for all `t`
C. `1/2xx(Eb b)/(Rm)xxt^2` for `tlet_0` and the wire stops
D. `1/2xx(Eb b)/(Rm)xxt^2` for `tlet_0` and `l+(EBb)/(Rm)xxt` for` tget_0`

Answer

a

Explanation

Use `F=Ibl sin theta` and the kinematics concepts.