The direction of magnetic field at a point due to an infinitely long wire carrying current is

The magnetic field generated by an infinitely long straight wire carrying current forms concentric circles in a plane perpendicular to the wire [t2][t3]. According to the Biot-Savart Law, the magnetic field vector (dB) at any point is determined by the cross product of the current element (dl) and the position vector (r) [t1]. This mathematical relationship dictates that the resulting magnetic field direction is always perpendicular to the plane containing both the conductor and the point of observation [t1]. This is practically determined using the right-hand thumb rule: when the thumb points in the direction of the current, the curled fingers indicate the direction of the magnetic field lines [t2][t5]. Consequently, the field has no components parallel to the wire or pointing directly toward/away from it; it is strictly tangential to the circular path [t6].