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

Given below are two statements:
Statement-$I$: $A$ point charge is brought into an electric field. The value of the electric field at a point near the charge may increase if the charge is positive.
Statement-$II$: An electric dipole is placed in a non-uniform electric field. The net electric force on the dipole will not be zero.
Choose the correct answer from the options given below:

Three point charges are placed at the corners of an equilateral triangle. Assuming only electrostatic forces are acting, which of the following statements is true?

Three point charges $q_1, q_2, q_3$ are placed at the vertices of a triangle. If the forces on $q_1$ and $q_2$ are $(2\hat{i} - \hat{j}) \, N$ and $(\hat{i} + 3\hat{j}) \, N$,respectively,then what will be the force on $q_3$?

There is a uniform spherically symmetric surface charge density at a distance $R_0$ from the origin. The charge distribution is initially at rest and starts expanding because of mutual repulsion. The figure that represents best the speed $V(R(t))$ of the distribution as a function of its instantaneous radius $R(t)$ is

Two identical positive charges are fixed on the $y$-axis, at equal distances from the origin $O$. $A$ particle with a negative charge starts on the $x$-axis at a large distance from $O$, moves along the $+x$-axis, passes through $O$, and moves far away from $O$. Its acceleration $a$ is taken as positive in the positive $x$-direction. The particle's acceleration $a$ is plotted against its $x$-coordinate. Which of the following best represents the plot?