Question 2.24:

What is the area of the plates of a 2 F parallel plate capacitor, given that the separation between the plates is 0.5 cm? [You will realize from your answer why ordinary capacitors are in the range of μF or less. However, electrolytic capacitors do have a much larger capacitance (0.1 F) because of the very minute separation between the conductors.]


 
The capacitance of a parallel capacitor, V = 2 F
Distance between the two plates, d = 0.5 cm = 0.5 x 10-2 m
Capacitance Of a parallel plate capacitor is given by the relation,
C=ϵ0AdA=Cdϵ0
Where,
ε0 = Permittivity of free space 
A=2×0.5×1028.85×1012=1130 km2
Hence, the area of the plates is too large.
To avoid this situation, the capacitance is taken in the range of μF.