Potential due to a Charged Spherical Shell

2024 1 question

1. A thin spherical shell is charged by some source. The potential difference between the two points $C$ and $P$ (in $V$) shown in the figure is; (Take $\frac{1}{4\pi\epsilon_0}=9\times10^{9}$ SI units, $R=3$ cm, $q=1\mu C$)