A uniform electric field exists in a region and is given by $\overrightarrow{E}=E_0\hat{\mathrm{i}}+E_0\hat{\mathrm{j}}$. There are four points $A(-a, 0)$, $B(0,-a), C(a, 0)$, and $D(0, a)$ in the $xy$ plane. Which of the following is the correct relation for the electric potential?

Two point charges $q_1$ and $q_2$ are placed in an external uniform electric field as shown in figure. The potential at the location of $q_1$ and $q_2$ are $V_1$ and $V_2$, respectively. The effect of $q_1$ and $q_2$ is not included in $V_1$ and $V_2$, i.e., $V_1$ and $V_2$ are potentials at location of $q_1$ and $q_2$ due to external unspecified charges only. Then electric potential energy for this configuration of two charged particle is

A negative charge is moved by an external agent in the direction of electric field. Then

Which of the following is true for the figure showing electric lines of force? ($E$ is an electrical field, and $V$ is potential.)

An uncharged conducting ball $B$ lies inside a charged conductor $A$ as shown in the figure. $B$ is isolated from $A$.