Question

why does a compass needle get deflected when brought near a bar magnet?​

Answer 1

The needle of a compass is a small magnet. That's why when a compass needle is brought near a bar magnet it's magnetic field lines interact with that of the magnet . Hence, a compass needle gets deflected.

Hope this will help you..

Answer 2

$\sf\purple{Answer :-}$

The compass needle is a small magnet. When the compass needle is brought close to a bar magnet, the magnetic field lines of the compass needle interact with the magnetic field lines of bar magnet, which causes the compass needle to deflect.