State important properties (or characteristics) of magnetic lines of force around a straight conductor.
The main properties are:
(i) The magnetic lines of force are in the form of concentric circles around the conductor but as their distance from the conductor increases, the curvature of lines of force decreases.
(ii) The direction of the magnetic lines of force reverses, if the direction of flow of current in the conductor reverses.
(iii) With the increase of current in the conductor, the number of lines of force or the intensity of magnetic field also increases.