B.3 Time dependent electrodynamics An infinitely long cylindrical solenoid of racfus a has n tums per unit length. The solenoid carries a current along the direction of a cylindrical system of coordinates with the z-axis situated along the axis of the solenoid. The current 1,0) is increasing with time (r) at a constant rate. In the q. approximation, the magnetic field of the solenoid is given by where s is the distance from the axis ot the solenod. A conducting circular ring ot wire of radius b and resistance R is coaxial with the solenoid (see the figure below). (i) Show that the following solution for the electric field inside and outside of the solenoid are a solution of Faraday's law tor this situation npo a2 dl npo [2 marks) (ii) Compute the current I, induced in the In which direction does the in- duced current flow? [5 marks]