The strength of the magnetic field around a conductor in air is:

The magnetic field produced by a wire is a direct result of electrons moving through it. According to the principles of electromagnetism, the strength of this magnetic field is directly proportional to the amount of current flowing through the conductor. It is important to remember that voltage alone does not create a magnetic field; there must be an actual flow of current. Additionally, while the diameter of the wire affects its physical resistance, it does not dictate the overall strength of the magnetic field outside the wire.