A capacitor consists of two circu. plates of radius a separated by a distance d (assume d <« a). 'In ` centre of each plate is connected to the terminals of a voltage sou. • by a thin wire. a d TE +Q A switch in the circuit is closed at time t = 0 and a current I(t) flows in the circuit. The charge on the plate is related to the current according to I (t) = dq/dt. We begin by calculating the electric field between the plates. Throughout this problem you may ignore edge effects. We assume that the electric field is zero for r>a. Choose for an Amperian loop, a circle of radius r < a in the plane midway between the plates. Calculate the line integral of the magnetic field around the circle.

A capacitor consists of two circu. plates of radius a separated by a distance d (assume d <« a). 'In ` centre of each plate is connected to the terminals of a voltage sou. • by a thin wire. a d TE +Q A switch in the circuit is closed at time t = 0 and a current I(t) flows in the circuit. The charge on the plate is related to the current according to I (t) = dq/dt. We begin by calculating the electric field between the plates. Throughout this problem you may ignore edge effects. We assume that the electric field is zero for r>a. Choose for an Amperian loop, a circle of radius r < a in the plane midway between the plates. Calculate the line integral of the magnetic field around the circle.