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+(E3b)/(Rm)xxt` for` tget_0` where `t_0=sqrt((2lmR)/(Ebb))`

Answer

a

Explanation

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