Question

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

Answer 1

A compass needle gets deflected due to the forces acting on its poles due to the magnetic field of the bar magnet

Answer 2

$\bf\huge\underline\red{Question}$

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

$\bf\huge\underline\blue{Answer}$

A compass needle is a small magnet itself. It has a north pole and a south pole. When north pole and south pole of the bar magnets are closer to those of compass needle, they attract or repel as per the properties of poles.