Electric Dipole Moment
A vector quantity measuring the strength and orientation of an electric dipole, pointing from the negative charge toward the positive charge.
Governing formula
p = q d, τ = p × E, U = -p · E
SI unit
C·m (or Debye)
In depth
The potential energy U of an electric dipole in an external field is minimized (U = -p E) when the dipole moment vector aligns parallel with the electric field vector.
Examples in the real world
Measuring polar molecular properties in physical chemistry, such as water's electric dipole moment (~1.85 Debye ≈ 6.17 × 10⁻³⁰ C·m).