The electric field due to an electric dipole at a distance $r$ from its centre in the axial position is $E$. If the dipole is rotated through an angle of $90^{\circ}$ about its perpendicular axis,the electric field at the same point will be

$A$ 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?

If ${E_a}$ is the electric field strength of a short dipole at a point on its axial line and ${E_e}$ is the electric field strength on the equatorial line at the same distance,then:

$A$ molecule of a substance has a permanent electric dipole moment of magnitude $10^{-29} \text{ C m}$. $2 \text{ mole}$ of this substance is polarized (at low temperature) by applying a strong electrostatic field of magnitude $10^6 \text{ V m}^{-1}$. What is the potential energy of the system? ($1 \text{ mole}$ of substance contains $6 \times 10^{23}$ molecules.)

An electric dipole is placed in an electric field generated by a point charge.

An electric dipole is placed in a uniform electric field $\vec{E}$ of magnitude $40\ N/C$. The graph shows the magnitude of the torque $\tau$ on the dipole versus the angle $\theta$ between the field $\vec{E}$ and the dipole moment $\vec{p}$. The magnitude of the dipole moment $\vec{p}$ is equal to: