An increase in current results in an increase in the magnitude of the magnetic field produced at a given point.

The deflection of the compass needle increases as the current in the copper wire is increased.

Magnetic field lines do not cross each other because, at the point of intersection, the compass needle would have to point towards two directions simultaneously, which is not possible.

The relative strength of the magnetic field is indicated by the degree of closeness of the field lines. A stronger magnetic field is associated with crowded field lines.

Inside a magnet, the direction of magnetic field lines is from its south pole to its north pole, forming closed curves.