Sources of Magnetic Fields (Physics)

Recall cards on the sources of magnetic fields. The Biot-Savart law: the field of a current element, the permeability of free space, the right-hand rule for the direction, and the field of a circular arc and a full loop. The magnetic field of a thin straight wire: B = mu_0 I/(2 pi R), concentric circular field lines, and the right-hand rule. The force between two parallel currents: attraction and repulsion, the historical ampere definition, and the pinch effect. The magnetic field of a current loop: the magnetic dipole moment, the on-axis field, and the inverse-cube dipole falloff. Ampere's law: the line integral of B, the enclosed current, the Amperian loop, when to use it versus the Biot-Savart law, and the field inside and outside a thick wire. Solenoids and toroids: the uniform interior field of a solenoid, the zero exterior field, and the toroid field. Magnetism in matter: atomic dipole moments, paramagnetism, diamagnetism, ferromagnetism, magnetic domains, hysteresis, susceptibility, and permeability.