A charge $+q$ is distributed over a thin ring of radius $r$ with line charge density $\lambda=q \sin ^{2} \theta /(\pi r)$. Note that the ring is in the $X Y$ - plane and $\theta$ is the angle made by $r$ with the $X$-axis. The work done by the electric force in displacing a point charge $+ Q$ from the centre of the ring to infinity is
equal to $q Q / 2 \pi \varepsilon_{0} r$
equal to $q Q / 4 \pi \varepsilon_{0} r$
equal to zero only, if the path is a straight line perpendicular to the plane of the ring
equal to $q Q / 8 \pi \varepsilon_{0} r$
Let $V$ and $E$ are potential and electric field intensity at a point then
Charges of $ + \frac{{10}}{3} \times {10^{ - 9}}C$ are placed at each of the four corners of a square of side $8\,cm$. The potential at the intersection of the diagonals is
As shown in the figure, charges $ + q$ and $ - q$ are placed at the vertices $B$ and $C$ of an isosceles triangle. The potential at the vertex $A$ is
Assume that an electric field $\vec E = 30{x^2}\hat i$ exists in space. Then the potential difference $V_A-V_O$ where $V_O$ is the potential at the origin and $V_A$ the potential at $x = 2\ m$ is....$V$
Value of potential at a point due to a point charge is