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

When a compass needle is brought near a bar magnet, it gets deflected due to the interaction between the magnetic fields generated by both the compass needle and the bar magnet. This deflection is a result of the magnetic force acting on the compass needle.

The Earth itself has a magnetic field, which causes the compass needle to align itself with the Earth's magnetic field and point towards the magnetic North Pole. However, when a bar magnet is brought near the compass needle, its magnetic field interacts with the Earth's magnetic field and causes a disturbance.

The bar magnet has two magnetic poles, known as the North pole (N) and the South pole (S). The North pole of the bar magnet attracts the South pole of the compass needle, while the South pole of the bar magnet attracts the North pole of the compass needle. As a result, the compass needle gets deflected and aligns itself with the magnetic field of the bar magnet.

This deflection occurs because magnetic fields exert forces on each other. The magnetic field lines of the bar magnet and the compass needle interact, causing a torque or turning force on the compass needle. This torque causes the needle to rotate until it aligns with the magnetic field lines of the bar magnet.

The amount of deflection depends on the strength and proximity of the bar magnet to the compass needle. When the bar magnet is closer to the compass needle, the magnetic field is stronger, resulting in a larger deflection of the needle.

This phenomenon of the compass needle getting deflected near a bar magnet is a fundamental principle of magnetism and has been used for centuries to navigate and determine directions. It is due to this property that compasses are widely used in various applications, including navigation, surveying, and scientific experiments related to magnetism.

In summary, the deflection of a compass needle when brought near a bar magnet is a result of the interaction between the magnetic fields generated by both the compass needle and the bar magnet. The magnetic forces cause the needle to align itself with the magnetic field lines of the bar magnet, resulting in the observed deflection.