Electrostatics

A solid metallic sphere has a charge \(+3 Q\). Concentric with this sphere is a conducting spherical shell having charge \(-\mathrm{Q}\). The radius of the sphere is '\(A\)' and that of the spherical shell is '\(B\)'. \((B > A)\). The electric field at a distance '\(\mathrm{R}\)' \((\mathrm{A} < \mathrm{R} < \mathrm{B})\) from the centre is ( \(\varepsilon_0=\) permittivity of vacuum)