An isolated conducting sphere whose radius $\;R=1 m \;$ has a charge $\;q=\large\frac{1}{9}\; \mu C\;$ .The energy density at the surface of the sphere is

Question

$(a)\;\large\frac{\in_{0}}{2}\;J/m^3\qquad(b)\;\in\;J/m^3\qquad(c)\;2 \in_{0} \;J/m^3\qquad(d)\;\large\frac{\in_{0}}{3}\;J/m^3$