- Magnetic Field is the region around a magnetic material or a moving electric charge within which the force of magnetism acts.
- A bar magnet is a rectangular piece of an object, made up of iron, steel or any other ferromagnetic substance or ferromagnetic composite, that shows permanent magnetic properties.
- It has two poles, a north and a south pole such that when suspended freely, the magnet aligns itself so that the northern pole points towards the magnetic north pole of the earth.
Magnetic field lines of a bar magnet emerge from the North Pole and terminate at the South Pole as shown in the figure below.
The magnetic field lines can be defined as imaginary lines that can be drawn along the magnetic field that is acting around any magnetic substance. The magnetic field lines possess certain properties,
- The magnetic field lines of a magnet form continuous closed loops.
- The tangent to the field line at any point represents the direction of the net magnetic field B at that point.
- The larger the number of field lines crossing per unit area, the stronger is the magnitude of the magnetic field B.
- The magnetic field lines do not intersect.