Dipole

Definition

A dipole consists of two equal and opposite electric charges separated by a small distance. It is characterized by its dipole moment, which quantifies the strength and direction of the dipole.

5 Must Know Facts For Your Next Test

1. The dipole moment $\vec{p}$ is calculated as $\vec{p} = q \cdot \vec{d}$, where $q$ is the charge and $\vec{d}$ is the separation vector between the charges.
2. The electric field created by a dipole decreases with distance more quickly than that of a single charge; specifically, it diminishes as $1/r^3$.
3. Dipoles align with external electric fields due to torque, minimizing their potential energy in the process.
4. In biological systems, molecular dipoles are crucial for interactions such as hydrogen bonding and the behavior of water molecules.
5. When placed in a non-uniform electric field, a dipole experiences both a torque and a net force.

Review Questions

• How do you calculate the dipole moment for a system with two charges?
• Why do dipoles tend to align themselves in an external electric field?
• How does the electric field produced by a dipole compare to that produced by a single point charge in terms of distance dependence?

Related terms

Electric Field: A region around charged particles or objects within which other charged particles experience an electric force.

Torque: A measure of how much a force acting on an object causes that object to rotate. For dipoles, torque aligns them with an external electric field.

Polarization: The process or phenomenon involving the alignment of charges within an object or molecule due to an external electric field.