
$(A)$ the elecric field at $O$ is $6 K$ along $O D$
$(B)$ The potential at $O$ is zero
$(C)$ The potential at all points on the line $PR$ is same
$(D)$ The potential at all points on the line $ST$ is same.
Statement$ -1$ : When a charge $q$ is take from the centre of the surface of the sphere its potential energy changes by $\frac{{q\rho }}{{3{\varepsilon _0}}}$
Statement$ -2$ : The electric field at a distance $r(r < R)$ from centre of the sphere is $\frac{{\rho r}}{{3{\varepsilon _0}}}$
[take $\ln 5=1.6, \ln 3=1.1]$

