What is the maximum charge that can be given to a sphere of diameter \(10cm\) if the breakdown voltage of air is \(2\times10^4 V/cm\)? Discussion: Dielectric breakdown is when current flows through an electrical insulator when the voltage applied across it...

A spherical capacitor has inner radius \(a\) and outer radius \(b\). It is filled with an inhomogeneous dielectric with permittivity $$ \epsilon=\epsilon_0K/r^2$$ for \(a<r<b\). The outer sphere is grounded and a charge is placed on the inner sphere. Find the...