$A$ neutral water molecule $(H_2O)$ in its vapor state has an electric dipole moment of magnitude $6.4 \times 10^{-30} \ C \cdot m$. How far apart are the molecule's centers of positive and negative charge?

$A$ point particle of mass $M$ is attached to one end of a massless non-conducting rod of length $L$. Another point particle of the same mass is attached to the other end of the rod. The two particles carry charges $+q$ and $-q$ respectively. This arrangement is placed in a region of uniform electric field $E$. When the rod makes a small angle $(< 5^o)$ with the direction of the field,what is the minimum time required for the rod to become parallel to the field?

The distance between the two charges $+q$ and $-q$ of a dipole is $r$. On the axial line at a distance $d$ from the centre of the dipole,the electric field intensity is proportional to:

Two charges $+q$ and $-q$ are placed at a distance $b$ apart as shown in the figure. The electric field at a point $P$ on the perpendicular bisector as shown is

$A$ point $Q$ lies on the perpendicular bisector of an electric dipole with dipole moment $p$. If the distance of $Q$ from the dipole is $r$ (where $r$ is much larger than the size of the dipole),then the electric field at $Q$ is proportional to:

The angle between the dipole moment and electric field at any point on the equatorial plane is (in $^{\circ}$)