Final answer:
Magnetic field lines about a current-carrying wire circle the wire in closed loops, and the direction of the field is given by the right-hand rule, with the field strength decreasing with distance from the wire.
Step-by-step explanation:
The magnetic field lines about a current-carrying wire circle the wire in closed loops. These field lines are tangent to concentric circles centered on the wire, indicating the circular nature of the field. This behavior is explained by Essential Knowledge 2.D.2, which states that the magnetic field vectors around a straight wire carrying electric current are tangent to these concentric circles, affirming that the field has no component toward the wire. The direction of the magnetic field can be determined using the right-hand rule, which states that if you hold the wire with your right thumb pointing in the direction of the current, your fingers will curl in the direction of the magnetic field lines. This rule helps visualize how the magnetic field encircles the wire. Additionally, as one gets farther from the wire, the concentric circles representing the magnetic field lines become more widely spaced, indicating that the strength of the magnetic field decreases with distance.