Question

Explain what is electric dipole moment?

Answer 1

Electric Dipole Moment:

1. Two equal and opposite charges separated by a very small distance are said to constitute an electric dipole.
2. The molecules of a dielectric medium placed in an electrostatic field behave like an electric dipole.
3. For example, in a $H_{2}O$ molecule, the positive and negative charge centers do not coincide but are separated from each other by a very small distance.
4. Hence, a $H_{2}O$ molecule can be considered an electric dipole.
5. We define the dipole moment $\overrightarrow{p}$ of a dipole constituted by two charges $+q$ and $-q$ separated by a distance $2a$ as a vector quantity and directed from $-q$ to $+q$.
6. It has the unit of coulomb-meter.

$\therefore$Electric dipole moment, $\overrightarrow{p}=q\times 2\overrightarrow{a}$