Page 152 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

Let’s imagine the magnetic lines of force as a cage around
a magnet. The number of magnetic lines of force passing
normal to unit area is the magnetic flux density of that
region.
Magnetic flux density is greater at the poles of a magnet.

What are the peculiarities of magnetic lines of force?
By means of an experiment using a magnetic needle,
draw the magnetic lines of force formed between (a)
magnets, as in Fig. 11.9(a).

Now place the north pole of one magnet near the south
pole of another magnet and try to draw the magnetic lines of
force between them as in Fig. 11.9(b). (b)
Fig. 11.9
From the drawing you have made, find out the peculiarities of
magnetic lines of force and write them down in your science
diary.

Magnetic lines of force do not intersect one another.
Magnetic lines of force bend sideways, when like poles of
magnets come near each other.

When unlike poles of magnets come close to each other,
the path of the magnetic lines of force is from the north
pole of one magnet to the south pole of the other magnet.

Magnetic force is experienced in all dimensions around a magnet.
This region around a magnet where the influence is felt is the
magnetic field.
You have understood that a magnet attracts magnetic
substances.
Make a list of substances attracted by a magnet.

cobalt
nickel

Does a magnetic substance attracted by a magnet get
a magnetic force?
Magnetic Induction

Bring a pin in contact with the pole of a bar magnet as
shown in Fig. 11.10. Is it not attracted? What if you
(a) (b)
bring another pin to the free end of the pin? What is Fig. 11.10
Basic Science VIII 151