An electric charge ${10^{ - 6}}\mu {\rm{C}}$ is placed at origin (0, 0)m of X-Y co-ordinate system. Two points P and Q are situated at $(\sqrt 3 ,\sqrt 3 ){\rm{m}}$ and $(\sqrt 6 ,0){\rm{m}}$ respectively. The potential difference between the points P and Q will be :
