A spherical capacitor has an inner sphere of radius 12 cm and an outer sphere of radius 13 cm. The outer sphere is earthed and the inner sphere is given a charge of `2.5muC`. The space between the concentric spheres is fillled with a liquid of dielectric constant 32.
(a) Determine the capacitance of the capacitor.
(b) What is the potential of the inner sphere ?
(c) Compare the capacitance of this capacitor with that of an isolated sphere of radius 12 cm. Explain why the latter is much smaller.

Explanation

(a) `5.5 xx 10^(-9) F`
(b) `4.5 xx 10^(2)` V
( c) `1.3 xx 10^(-11)` F