Consider a system of three charges $\frac{\mathrm{q}}{3}, \frac{\mathrm{q}}{3}$ and $-\frac{2 \mathrm{q}}{3}$ placed at points $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$, respectively, as shown in the figure,
Take $\mathrm{O}$ to be the centre of the circle of radius $\mathrm{R}$ and angle $\mathrm{CAB}=60^{\circ}$
Figure:$Image$
The electric field at point $O$ is $\frac{\mathrm{q}}{8 \pi \varepsilon_0 \mathrm{R}^2}$ directed along the negative $\mathrm{x}$-axis
The potential energy of the system is zero
The magnitude of the force between the charges at $C$ and $B$ is $\frac{q^2}{54 \pi \varepsilon_0 R^2}$
The potential at point $\mathrm{O}$ is $\frac{\mathrm{q}}{12 \pi \varepsilon_0 \mathrm{R}}$
A proton is accelerated through $50,000\, V$. Its energy will increase by
Electrostatic potential energy of given system will be
A proton of mass $m$ and charge $e$ is projected from a very large distance towards an $\alpha$-particle with velocity $v$. Initially $\alpha$-particle is at rest, but it is free to move. If gravity is neglected, then the minimum separation along the straight line of their motion will be
Why gravitational forces or spring forces are conservative forces ?
Consider the configuration of a system of four charges each of value $+q$ . The work done by external agent in changing the configuration of the system from figure $(1)$ to figure $(2)$ is