State Ampere’s law

Ampere's Law states that the magnetic field in space around an electric current is proportional to the electric current which serves as its source, just as the electric field in the space around an electric charge is proportional to the charge which serves as its source. Ampere's Law is defined mathematically as:

∮ B . dl = μ0 * I

Where:

• ∮ B . dl is the magnetic field B integrated over a closed loop (a path that starts and ends at the same point).
• μ0 is the permeability of free space.
• I is the electric current passing through that closed loop.

This law is used in electromagnetism to calculate the magnetic field generated by a given current distribution.