What does the analog (similarity) of bar magnet's and solenoid's magnetic field lines suggest ?

Explanation

The analogy (similarity) of the magnetic field lines of the bar magnet and solenoid is shown as follows:
(i) A bar magnet may be thought of as a large number of circulating current in analog with a solenoid.
(ii) Cutting a bar magnet in half the each piece behave like an independent magnet. Cutting a solenoid from middle we get two smaller solenoids with weaker magnetic properties.
(iii) Like a bar magnet, the magnetic lines in the solenoid are continuous emerging from one face of the solenoid and entering into the other face and form a closed loop.
(iv) Like a bar magnet the magnetic field at point on the axis, the magnetic field of solenoid at point on axis is `B = (mu_(0) ) /( 4 pi) (2m)/( r^3)`.