A parallel plate capacitor with circular plates of radius 0.8 m has a capacitance of 1 nF. At t = 0, it is connected for charging in series with a resistor `R = 1 M Omega` across a 4V battery. Calculate the magnetic field at a point P, halfway between the centre and the perpendicular of the plates after `t=10^(-3)s`. (The charge on the capacitor at time t is q (t) = CV [1 - exp `(-t//tau)`], where the time constant `tau` is equal to CR.)

Explanation

`i_(d)=0.3679xx10^(-6)A, B=1.84xx10^(-13)T`.