58. A metal rod is pulled to the right in a uniform magnetic field

so that itaccelerates at a constant acceleration

on rails and forms a closed circuit with aresistor R as shown in Fig. 12. For simplicity, let us say at t = 0, the metal rodcoincides with the resistor at x = O and is at rest. The distance between rails is L.Assume that there is no friction between the rod and rails. Which of the followingstatements is correct?

(A) The emfinduced by pulling theUniform magnetic field Bozmetal rod is proportional to t2.
(B) The force required to pull the metalrod is proportional to t.
(C) The power dissipation in resistor isproportional to t3.
(D) The work done by the pulling force isproportional to t.
(E) None of the above is correct.