The plates of a parallel-plate capacitor are made of circular discs of radii 5.0 cm each. If the separation between the plates is 1.0 mm, what is the capacitance ?
Area of the plate
A=πr2=π×(5×10−2)2
d=1.0×10−3 m
C=∈0 Ad
=8.8×10−12×3.14×25×10−410−3
=695×10−5 μF