# 2.30 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 2.5 $\mu C$. The space between the concentric spheres is filled with a liquid of dielectric constant 32. (b) what is the potential of the inner sphere?

$V=\frac{q}{C}=\frac{2.5*10^{-6}}{5.5*10^{-9}}=4.5*10^2$
Hence the potential of the inner sphere is $4.5*10^2 V$.