The potential in an electric field varies as $V = (x^2 - y^2)$. The electric lines of force in the $X-Y$ plane are

The distance between two charges $25\,\mu C$ and $36\,\mu C$ is $11\,cm$. At what point on the line joining the two charges will the electric field intensity be zero?

Four point positive charges of same magnitude $Q$ are placed at four corners of a rigid square frame in $xy$ plane as shown in the figure. The plane of the frame is perpendicular to the $z$-axis. If a negative point charge is placed at a distance $z$ away from the above frame $(z << L)$,then:

The equation of an electric field line in the $xy$-plane is given by ${x^2} + {y^2} = 1$. What is true for a particle with unit positive charge initially at rest at the point $(1, 0)$ in the $xy$-plane?

Explain electric field and its source as well as magnetic field and its source.

$A$ sphere $A$ of radius $R$ has a charge $Q$ on it. The electric field at point $B$ at a distance $r$ from the center of sphere $A$ is $E$. Now,another sphere of radius $2R$ having a charge $-2Q$ is placed at $B$. What is the magnitude of the total electric field at the point midway between $A$ and $B$ due to both spheres?