question_answer 47)

  Find the current in the sliding rod AB (resistance = R) for the arrangement shown in Fig. 4(EP).21. B is constant and is out of the paper. Parallel wires have no resistance,  is                 constant. Switch S is closed at time t = 0. 

Answer:

                                           Proceeding as in Q. 29 above,  or                   ???(i) where A is an arbitrary constant. At t = 0, = 0 From (i), Putting this value of  in (i), we get This is the required current in sliding rod AB.