When current flows in a wire, a magnetic field is produced around the wire in the form of concentric circles. The intensity of magnetic field is reduced as the distance from the wire is increased.
The direction of magnetic field produced by a wire carrying electric current is determined by Ampere’s right-hand rule, which can be stated as follows:
- If you wrap right-hand fingers around a current-carrying wire such that your thumb points to the direction of current, your fingers will be showing the direction of magnetic field.
- Dot = Arrowhead (flying at you)
- X = Arrow feathers (flying away from you)