Electric Dipole:
- An electric dipole is a pair of equal and opposite charges separated by a small distance.
- Electric dipoles can be either permanent (e.g. a water molecule) or induced (e.g. an atom in an external electric field).
- An electric dipole creates an electric field that is different from that of a single charge, with a dipole moment that depends on the separation distance and the magnitude of the charges.
Electric dipole moment:
- The electric dipole moment is a measure of the strength of an electric dipole.
- It is defined as the product of the separation distance between the charges and the magnitude of the charges.
- Mathematically, the electric dipole moment is given by
- p = qd,
- where p is the dipole moment, q is the magnitude of the charge, and d is the separation distance between the charges.
- The unit of electric dipole moment is coulomb-meter (Cm).
- The direction of the electric dipole moment is from the negative charge to the positive charge.
Some additional notes:
- The electric dipole moment is a vector quantity, with direction determined by the direction of the separation distance between the charges.
- The electric field created by an electric dipole decreases as the inverse cube of the distance from the dipole.
- The torque (or turning effect) experienced by an electric dipole in an external electric field is proportional to the product of the electric field and the dipole moment
