Consider a system of three charges $\frac{q}{3},\frac{q}{3}$ and $-\frac{2q}{3}$ placed at points A, B and C respectively which lie on a circle with O to be the center with radius R and angle $CAB={60}^0$. If AB is the diameter of the circle, choose the correct statement

Electric field at the centre is due to the charge C which is given as $E=\frac{1}{4\pi {\in }_0}\frac{(2q/3)}{R^2}=\frac{q}{6\pi {\in }_0{R}^2}$
Potential energy of the system is, given as  $U=\frac{1}{4\pi {\in }_0}[\frac{\frac{q}{3}\times \frac{q}{3}}{2R}+\frac{\frac{q}{3}(-\frac{2q}{3})}{\sqrt{3}R}+\frac{\frac{q}{3}(-\frac{2q}{3})}{R}]\ne 0$
Force between charges B and C is given as $F_{BC}=\frac{1}{4\pi {\in }_0}\left[\frac{\frac{q}{3}\left(\frac{2q}{3}\right)}{{\left(\sqrt{3R}\right)}^2}\right]=\frac{q^2}{54\pi {\in }_0{R}^2}$