A thin spherical insulating shell of radius $R$ carries a uniformly distributed charge such that the potential at its surface is $V _0$. A hole with a small area $\alpha 4 \pi R ^2(\alpha<<1)$ is made on the shell without affecting the rest of the shell. Which one of the following statements is correct?
The ratio of the potential at the center of the shell to that of the point at $\frac{1}{2} R$ from center towards the hole will be $\frac{1-\alpha}{1-2 \alpha}$
The magnitude of electric field at the center of the shell is reduced by $\frac{\alpha V_0}{2 R}$
The magnitude of electric field at a point, located on a line passing through the hole and shell's center on a distance $2 R$ from the center of the spherical shell will be reduced by $\frac{\alpha V_0}{2 R}$
The potential at the center of the shell is reduced by $2 \alpha V _0$
Two charge $ + \,q$ and $ - \,q$ are situated at a certain distance. At the point exactly midway between them
Figure shows three circular arcs, each of radius $R$ and total charge as indicated. The net electric potential at the centre of curvature is
Two charges ${q_1}$ and ${q_2}$ are placed at $(0, 0, d)$ and$(0, 0, - d)$ respectively. Find locus of points where the potential is zero.
Three charged concentric nonconducting shells are given as shown in figure. Find the potential at point $A$
Twenty seven drops of same size are charged at $220\, \mathrm{~V}$ each. They combine to form a bigger drop. Calculate the potential of the bigger drop. (In $\mathrm{~V}$)