Two large, identical circular plates of radius R=5.0cm form an air-filled capacitor. During the charging process the conduction current in the leads is
I(t)=0.50sin(2000t)A,
with t in seconds. The field between the plates is uniform. Neglect edge effects.
(a) Derive an expression for the magnetic field B(r,t) at a distance r(<R) from the common axis of the plates due solely to the current in the region between the plates.
(b) Using the expression obtained, calculate the magnitude of B at the point located r=2.0cm from the axis at the instant t=1.25ms.
(c) Comment on how the magnetic field inside the capacitor compares with that just outside the connecting wire at the same distance from the axis when the conduction current equals its instantaneous value given above.