Question

What are magnetic field lines,? How is the direction of the magnetic field at a point determined? Draw the patterns of the field lines due to a bar magnet. List three properties of magnetic field lines.

Answer 1

Definition of field lines and direction of magnetic field

1. Magnetic field lines are imaginary smooth curves that are used to pictorially represent the magnetic field.
2. The tangent to the magnetic field line at any point gives the direction of the magnetic field at that point.
3. The direction of the magnetic field at a point can also be found by placing a magnetic compass at that point and the north pole of the compass will give the direction of the magnetic field at that point.

Pattern of field lines due to a bar magnet

Properties of magnetic field lines.

1. Magnetic field lines are closed curves that are directed from the north pole to the south pole outside the magnet and from the south pole to the north pole inside the magnet.
2. The tangent to the magnetic field line at any point gives the direction of the magnetic field at that point.
3. Two magnetic field lines cannot intersect each other because at the point of intersection two tangents can be drawn which means two directions of magnetic field at a point that is not possible.