Which of the following correctly describes the magnetic field near a long straight wire?
a. The field consists of straight lines perpendicular to the wire.
b. The field consists of straight lines parallel to the wire.
c. The field consists of radial lines originating from the wire.
d. The field consists of concentric circles centered on the wire.
Which of the following correctly describes the magnetic field near a long straight wire?
a. The field consists of straight lines perpendicular to the wire.
b. The field consists of straight lines parallel to the wire.
c. The field consists of radial lines originating from the wire.
d. The field consists of concentric circles centered on the wire.

d. The field consists of concentric circles centered on the wire.

Concentric circles form the magnetic field around a long straight wire. Their centres are on the wire.