A massless non conducting rod AB of length 2l is placed in uniform time varying magnetic field confined in a cylindrical region of radius `(R gt l)` as shown in the figure. The center of the rod coincides with the centre of the cylin- drical region. The rod can freely rotate in the plane of the Figure about an axis coinciding with the axis of the cylinder. Two particles, each of mass m and charge q are attached to the ends A and B of the rod. The time varying magnetic field in this cylindrical region is given by `B = B_(0) [1-(t)/(2)]` where `B_(0)` is a constant. The field is switched on at time `t = 0`. Consider `B_(0) = 100T, l = 4 cm(q)/(m) = (4pi)/(100) C//kg`. Calculate the time in which the rod will reach position CD shown in the figure for th first time. Will end A be at C or D at this instant ?

Answer

1,s end A