Finding Directions

The Freely Suspended Magnet

One of the most useful properties of a magnet is its ability to find direction.

Activity:

1. Take a bar magnet and tie a thread to its center.
2. Suspend it freely so it can rotate horizontally.
3. Wait for it to come to rest.

Observation: The magnet always comes to rest in the same direction: North-South.

• The end pointing towards the North is called the North-seeking pole or North Pole.
• The end pointing towards the South is called the South-seeking pole or South Pole.

Why does this happen? Because the Earth itself acts like a giant magnet.

The Magnetic Compass

A magnetic compass is a device used by travellers to find directions based on this property.

Construction

• It consists of a small circular box with a glass cover.
• Inside, a magnetized needle is pivoted at the center so it can rotate freely.
• The needle usually has its North pole painted red.
• The dial has directions (N, S, E, W) marked on it.

Making Your Own Compass (Activity 4.4)

1. Magnetize a Needle: Take an iron sewing needle. Rub a bar magnet along its length in one direction only (lifting it at the end and bringing it back to the start). Repeat 30-40 times.
2. Float It: Insert the magnetized needle into a small piece of cork or foam.
3. Observe: Float the cork in a bowl of water. The needle will align itself in the North-South direction.