Isolated spherical conductor
1. Capacitance of an isolated spherical conductor of radius ‘a’ is Cearth = 4 πε0 a
2. As C ∝ a, thus big spheres have more capacitance than small spheres.
3. If the spherical isolated conductor is earthed, then entire charge leaks to earth, making its potential zero & thus C = ∞.
4. For earth capacitance is