关键词: 电偶极子, 磁偶极子, 电荷密度, 电流密度, 力, 力矩, δ函数

Abstract: In terms the expressions of the charge density for an electric dipole, the force and torque exerted by an external electric field on it are derived in a simple way by using the δ function. The same thing is also done for an magnetic dipole in external magnetic field.

Key words: electric dipole, magnetic dipole, charge density, current density, force, torque, δ function