8.5 Magnetic Fields
When a magnet attracts a certain magnetic material, it exerts some force to do so. Similarly, when it attracts or repels a magnetic pole of another magnet, it exerts a force on it. This force can be observed up to a certain distance from the magnet.
lightbulbA magnetic field is the region around a magnet where another magnetic object experiences a force on it.
The pattern of a magnetic field around a bar magnet can be seen very easily by a simple experiment. If iron filings are sprinkled on a thin glass plate placed over a bar magnet and the glass surface is gently tapped, the filings form a pattern. This pattern is known as the magnetic field pattern. This pattern can be better shown by lines that correspond to the path of the filings. These lines are called magnetic lines of force.
The magnetic lines of force around a bar magnet can also be drawn by using a small compass. The needle of the compass will move along the magnetic lines of force.