Question

compare the strenght of field near the poles and middles of bar magnet

Answer 1

To compare the magnetic field we need a magnet and ans some iron paper clips take all the clips and atich them to the magnet you will see that more clips will stick to the ends while on the middle less clips are stuck

Answer 2

The field lines are closely packed at either pole of the magnet, widening as they get further from the pole and connecting to the opposite pole of the magnet. The magnetic field lines emerge from the north pole and enter the south pole. The magnetic field gets weaker the further you get from either pole, so a bar magnet is only useful for picking up small items over short distances.