Explore the practical and theoretical significance of understanding the magnetic force between parallel conductors, crucial for electromagnetism and modern technology.

What happens if we take a wire, drill a hole in it and set some current in motion? Will we encounter a magnetic field?

The magnetic field of a thin and infinitely long wire is calculated using Biot-Savart's law.

We calculate the magnetic field of a wire with constant current. Using symmetries we verify the right-hand rule.

The magnetic field for a current distribution in form of a cylinder shell is determined.

Helmholtz coils are a devices that can provide a very homogeneous magnetic field. Let's find an approximation for their magnetic field!

Through physical reasoning we find that the spin of the electron cannot be explained by a classical rotation.

The Proca-formulation of electrodynamics allows to account for a hypothetical massive photon. This formulation is formally equivalent to the London theory of superconductivity

Using the magnetostatic potential can be extremely useful to calculate magnetostatic problems. In this example we use it to derive the magnetic field of a sphere with surface current.