First find RB, dl, the line integral of B around a loop of radius R located just outside the left capacitor plate. This can be found from the usual current due to moving charge in Ampère's law, that is, without the displacement current. Find an expression for B Right arrow d Right arrow, the same line integral of B Right arrow around the same loop of radius R located just outside the left capacitor plate as before. Use the surface that passes between the plates of the capacitor, where there is no conduction current. This should be found by evaluating the amount of displacement current in the Ampere-Maxwell law above.