In order to obtain magnetic field lines around a bar magnet, a student performed an experiment using a…
In order to obtain magnetic field lines around a bar magnet, a student performed an experiment using a magnetic compass and a bar magnet. The magnet was placed on a sheet of white paper fixed on a drawing board. Using magnetic needle he obtained on the paper a pattern of magnetic field lines (as shown below) around the bar magnet.
(a) By convention, the field lines emerge from north pole and merge at south pole. Why ? Give reason.
(b) State the relationship between strength of the magnetic field and the degree of closeness of the field lines.
(c) (A) (i) No two field lines can ever intersect each other. Give reason.
(ii) The magnetic field in a given region is uniform. Draw a diagram to represent it.
Solution
(a) The direction of the magnetic field is taken to be the direction in which a north pole of the compass needle moves inside it.
(b) Closer the field lines stronger is the magnetic field.
(c) (A) (i) It would mean that at the point of intersection, the compass needle would point towards two directions, which is not possible.
(ii) [Diagram: Equidistant parallel lines]
Equidistant parallel lines
(Award marks if magnetic field is shown through a solenoid)