When a straight wire is bent into a circular loop and current is passed through it, the pattern of magnetic field lines changes. Initially, for a straight wire, the field lines form concentric circles around the wire. However, when the wire is bent into a loop, the field lines now encircle the loop, creating a pattern resembling multiple concentric circles within the loop. At the center of the loop, the field lines align perpendicular to the plane of the loop, forming a more structured and concentrated pattern. This change in configuration reflects the altered geometry and symmetry introduced by the circular loop.