Question

maximum iron filling stick to the two ends of a bar magnet why

Answer 1

Because magnetic field lines strength is most near 2 ends of a bar magnet....

Answer 2

Heya !!!!

This is your answer.....

Most of the iron filings when brought near the magnetic field stick to the both ends of the bar magnets.....

Why so???

It is because the magnetic force is stronger at the ends than in the middle.

One more question arises...
Why is the magnetic force of attraction strongest at the ends??

We know that magnetic force of attraction is due to magnetic field lines which is around the magnet.
It is from North pole to South pole.

In the middle, these lines get far from each other whereas at the ends, they are very near to each other.

More the magnetic field lines in a area, stronger the force will be.
Hence. magnetic force is strongest at the ends. So. maximum iron filling stick to the two ends of a bar magnet.

Hope it helps ....