Identify the correct statements:
$A$. Electrostatic field lines form closed loops.
$B$. The electric field lines point radially outward when charge is greater than zero.
$C$. The Gauss-Law is valid only for inverse-square force.
$D$. The work done in moving a charged particle in a static electric field around a closed path is zero.
$E$. The motion of a particle under Coulomb's force must take place in a plane.
Choose the correct answer from the options given below:

Two identical charged spheres are suspended from a common point by two massless strings of length $l$. Initially,they are at a distance $d$ $(d << l)$ due to mutual repulsion. The charge begins to leak from both spheres at a constant rate. As a result,the spheres approach each other with a velocity $v$. Then,the velocity $v$ as a function of the distance $x$ between them is:

$A$ uniformly charged thin spherical shell of radius $R$ carries a uniform surface charge density of $\sigma$ per unit area. It is made of two hemispherical shells, held together by pressing them with force $F$ (see figure). $F$ is proportional to

An oil drop carries six electronic charges,has a mass of $1.6 \times 10^{-12} \text{ g}$ and falls with a terminal velocity in air. The magnitude of the vertical electric field required to make the drop move upward with the same speed as it was formerly moving is ........$kN/C$.

The diagram shows three infinitely long uniform line charges placed on the $X, Y$ and $Z$ axes with linear charge densities $2\lambda, 3\lambda$ and $\lambda$ respectively. The work done by an external agent in moving a unit positive charge from $(1, 1, 1)$ to $(0, 1, 1)$ is equal to:

Given below are two statements:
Statement $I$: An electric dipole is placed at the centre of a hollow sphere. The flux of electric field through the sphere is zero,but the electric field is not zero anywhere in the sphere.
Statement $II$: If $R$ is the radius of a solid metallic sphere and $Q$ is the total charge on it,the electric field at any point on a spherical surface of radius $r$ ( < R ) is zero,and the electric flux passing through this closed spherical surface of radius $r$ is also zero.
In the light of the above statements,choose the correct answer from the options given below: