Eight identical charged drops combine to form a single large drop. If the potential of each small drop is $10 \ V$,then the potential of the large drop will be ........ $V$?

Along the $x$-axis,three charges $\frac{q}{2}, -q$ and $\frac{q}{2}$ are placed at $x=0, x=a$ and $x=2a$ respectively. The resultant electric potential at a point $P$ located at a distance $r$ from the charge $-q$ $(r > a)$ is ($\varepsilon_0$ is the permittivity of free space):

The electric potentials at two points $P$ and $Q$ are $10 \ V$ and $-4 \ V$ respectively. The work done in moving $100$ electrons from $P$ to $Q$ is:

The electric potential at a distance $r$ outside a uniformly charged sphere (where $a$ is the radius of the sphere) is proportional to:

Three charged concentric nonconducting shells are given as shown in the figure. Find the potential at point $A$.

$A$ nerve fiber membrane separates two conducting fluids and maintains a constant potential difference. What is the order of this potential difference?