Which of the following will correctly describe the magnetic field near a long straight wire?

The field consisting of concentric circles centred on the wire correctly describes the magnetic field near a long straight wire. Magnetic field:

(a) The magnetic field is defined as an invisible field that exerts a magnetic force on magnetism-sensitive substances. 

(b) Magnetic field lines do not cross each other. 

(c) Magnetic field lines always make closed loops. 

(d) The magnetic field lines always begin from the north pole and terminate at the south pole. 

(e) The density of the field lines denotes the strength of the field. 

Magnetic field lines of a long straight wire:

(a) The magnetic field lines of a long straight wire are composed of concentric circles centred around the wire. 

(b) The right-hand thumb rule gives the direction of magnetic field lines. 

An illustrative diagram of magnetic field lines of a long straight wire:

Therefore, option (d) The field consists of concentric circles centred on the wire is correct.