$A$ circle of radius $R$ is drawn with a charge $+q$ at the centre. $A$ charge $q_0$ is moved from point $B$ to $C$ along the circumference of the circle. The work done is:

$A$ charge $+Q$ is placed at the centre of a circular path of radius $r$. The work done to bring a charge $+q$ from one end of the diameter to the other end of the circular path in the electric field produced by charge $+Q$ is $.......$

Positive and negative point charges of equal magnitude are kept at $(0, 0, a/2)$ and $(0, 0, -a/2)$,respectively. The work done by the electric field when another positive point charge is moved from $(-a, 0, 0)$ to $(0, a, 0)$ is

Define an equipotential surface.

The figure shows lines of constant potential in a region where an electric field is present. The electric field at point $B$ is............

$A$ hollow conducting sphere is placed in an electric field produced by a point charge placed at $P$ as shown in the figure. Let $V_A, V_B, V_C$ be the potentials at points $A, B,$ and $C$ respectively. Then: