Earth’s Magnetism

EARTH’S MAGNETISM

If a bar magnet, with its ends marked North and South, is freely suspended then the North end of the magnet seeks geographic North pole (which is actually Magnetic South Pole). Since earth is a huge magnet in itself the North pole is attracted by the South magnetic pole of the earth. Similarly, Earth’s magnetic north pole is geographic South pole. Earth’s geographical poles and magnetic poles are not the same.

The magnetic pole is found deep inside the northern and southern hemisphere of the earth (not on the Earth’s surface).

How a magnetic compass works:

A magnetic compass works because the Earth is like a giant magnet, surrounded by a huge magnetic field

The Earth has two magnetic poles which lie near the North and South poles

The magnetic field of the Earth causes a magnetized 'needle' of iron or steel to swing into a north-south position if it is hung from a thread.

How to use a Magnetic compass:

The red painted part of the needle is always pointing towards the earth's magnetic north pole. Housing of compass can be rotated turned through scale 0 to 360⁰.

How to find the direction?

Let’s say, we wish to navigate ship towards North-West

1. Turn the compass housing such that north-west on the housing coincides with travel-arrow.

2. Hold the compass in your hand such that it is in horizontal position or keep it on flat surface (so that the compass needle can turn)

3. Turn the entire compass without turning the compass housing, until the compass needle is aligned with the lines inside the compass housing.