NEET UG PHYSICS MCQ: ELECTRIC FIELDS AND CHARGES

A solid sphere of radius ${R_1}$ and volume charge density $\rho = \frac{{{\rho _0}}}{r}$ is enclosed by a hollow sphere of radius ${R_2}$ with negative surface charge density $\sigma$, such that the total charge in the system is zero, ${\rho _0}$ is a positive constant and $r$ is the distance from the centre of sphere. The ratio $\frac{{{R_2}}}{{{R_1}}}$ is