The magnetic field of a bar magnet is the strongest ___.

A: it is the same throughout the magnet

B: at the poles of the magnet

C: only on the north pole side of the magnet

D: in the middle of the magnet

The magnetic field is strongest at the part where the magnetic field lines are more, which is at the poles.

Answer : Option B

Explanation:

The strength of magnetic field is strongest in a bar magnet at either of the poles. The polarity is established by the magnetic field lines and they are in abundance at the poles too.

Therefore, they are strongest at the poles. The center of the magnet has the weakest strength of the magnetic field which decreases from either side of the poles towards the center.

B) at the poles of the magnet