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 $q Q / 8 \pi \varepsilon_{0} r$
The potential at a distance $R/2$ from the centre of a conducting sphere of radius $ R$ will be
Two point charges $4\,\mu C$ and $ - 1\,\mu C$ are kept at a distance of $3\ m$ from each other. What is the electric potential at the point where the electric field is zero?......$V$
Six point charges are placed at the vertices of a regular hexagon of side $a$ as shown. If $E$ represents electric field and $V$ represents electric potential at $O$, then
Let $V$ and $E$ are potential and electric field intensity at a point then
$125$ identical drops each charged to the same potential of $50\;volts$ are combined to form a single drop. The potential of the new drop will be......$V$