Question

What does the divergence of magnetic field lines near the ends of a current carrying straight solenoid indicate?

Answer 1

Hint: Field lines pass through the coils, and the field begins pointing out from the solenoid's ends and turning around to go back to the other end of the solenoid. The divergence (degree of closeness) of magnetic field lines close to the ends of a current-carrying a straight solenoid indicates a decrease in the magnetic field's strength near the solenoid's ends.

Complete answer: A solenoid is a coil of wire with many turns wrapped on it. The magnetic field inside a solenoid depends on the current and number density and its direction on the current direction. The field lines have to go about in loops because they cannot start or end anywhere. Field lines enter through the coils, and the field begins pointing out from the boundaries of the solenoid and rolling around to go back to the other end of the solenoid. It is the "fringe field" of the solenoid.
When a current moves through it, it produces an approximately uniform magnetic field inside or at the solenoid axis. Outside the solenoid, it is small and appears to diverge at the ends and beyond the magnetic field. This divergence is due to the distance from the current-carrying solenoid increases. The divergence of magnetic field lines shows the decrease in the magnetic field's strength near the solenoid's ends. The falling degree of closeness of magnetic field lines shows the fall in the magnetic field's power near and beyond the solenoid's ends. The distance from the current-carrying conductor and the magnetic field are inversely proportional. That is, as distance rises, magnetic field strength drops.

Additional Information:
We can change the field shape by covering your solenoid around an iron core, and if the iron core loops back around to go back in the other end of the solenoid, the fringe field can be reduced. Iron has a large magnetic permeability and magnetic field lines inside the iron. The magnetic field strength would nearly be the equivalent on the ends of the solenoid as in the centre.

Note:
The magnetic field lines' divergence near the ends of a current-carrying straight solenoid symbolizes that the solenoid acts like a magnet as magnet field lines form the loop around a magnet. Similarly, the divergence of magnetic field lines near the current-carrying straight solenoid ends indicates that the solenoid behaves like a magnet.