An electric current flowing through a wire produces a magnetic field around it. This relationship between magnetic fields and electric currents is a fundamental concept in physics. Understanding this relationship helps us comprehend various phenomena and design essential devices.

To determine the direction of the magnetic field created by an electric current, we can apply the right-hand rule. Imagine grasping the wire with your right hand, with your thumb pointing in the direction of the current flow. The curled fingers then indicate the direction of the magnetic field lines encircling the wire.

For instance, consider a straight wire with an electric current flowing from left to right. Applying the right-hand rule, we find that the magnetic field lines wrap counterclockwise around the wire. If the current direction were reversed, the magnetic field lines would change direction accordingly.

It is worth noting that the strength of the magnetic field produced by an electric current depends on various factors, including the magnitude of the current, the distance from the wire, and the permeability of the surrounding medium. These factors collectively determine the magnetic field's intensity and shape.