An electric dipole is a system consisting of two equal and opposite charges separated by a small distance.
Definition
An electric dipole consists of:
- One positive charge (+q)
- One negative charge (−q)
- A fixed distance between them
Representation
It is usually represented as:
(+q) —— d —— (−q)
Where:
- q = magnitude of charge
- d = distance between charges
Dipole Moment
The strength of a dipole is measured by its dipole moment (p).
Formula:
p = q × d
- Direction: From negative to positive charge
- Unit: Coulomb-meter (C·m)
Key Characteristics
- Charges are equal in magnitude but opposite in sign
- The separation distance is small but finite
- Creates an electric field around it
Example
- A molecule like HCl (Hydrogen Chloride) acts as a dipole
- A simple system of two charges (+q and −q) separated by distance
Practical Understanding
Electric dipoles are important in:
- Electrostatics
- Molecular physics
- Capacitors and electric fields