Suppose, one wishes to construct a 1.0-f capacitor using circular discs. If the separation between the discs be kept at 1.0 mm, what would be the radius of the discs?
Given:
C = 1 F
d=1 mm
Formula used :
Capacitance is given by
Where
C is the capacitance of the capacitor
D is the separation between the capacitor plates
A is the area of a circular plate capacitor
ε₀ is the permittivity of the free space=8.85×10-12 F/m
A = area of the circle =.Because capacitor plates are circular discs.
=6×103 m=6000 m=6 km
For the construction of 1F capacitor with 1mm separation, we need to take the radius r=6 Km.