The number of electrons to be put on a spherical conductor of radius $0.1\,m$ to produce an electric field of $0.036\,N/C$ just above its surface is:

There is an electric field $E$ in the $X$-direction. If the work done on moving a charge $0.2\,C$ through a distance of $2\,m$ along a line making an angle $60^\circ$ with the $X$-axis is $4.0\,J$,what is the value of $E$ in $N/C$?

At a certain distance from a point charge,the electric field is $500 \ V/m$ and the potential is $3000 \ V$. What is this distance (in $m$)?

The electric field at the centre $O$ of a semicircle of radius $a$ having a linear charge density $\lambda$ is given by:

Charges $Q_{1}$ and $Q_{2}$ are at points $A$ and $B$ of a right-angled triangle $OAB$ (see figure). If the resultant electric field at point $O$ is perpendicular to the hypotenuse $AB$,then $Q_{1} / Q_{2}$ is proportional to:

$A$ uniformly charged sphere has a total charge $Q$ and radius $R$. The electric field $E$ is a function of the distance $r$ from the center. Which of the following graphs represents this relationship?