A compass is a device that is used to find the direction.
It consists of a glass box and a needle. A magnetic needle rotates freely inside the box. A dial is placed inside the box with directions marked on it. The needle coloured in red shows the magnetic north pole of the earth.
Uses of compass:
- A compass is mainly used in ships and aeroplanes for navigation.
- Mountaineers carry a compass to the unknown places to find their way out.
A mountaineer with a compass
We can make our magnet with the help of a bar magnet.
Rubbing a bar magnet on an iron nail
- Place a rectangular piece of iron or a nail on the table.
- Place one end (pole) of a bar magnet near one edge of the iron piece or a nail.
- Till you reach the other end, move the bar magnet along the length of the iron or a nail.
- Now, bring the pole to the starting point of the iron or a nail and move it in the same direction again.
- Note that the pole of the magnet and its direction should not change.
- Repeat this process several times (around \(30\) to \(40\) times).
- Now, check whether it has become a magnet by placing a pin or some iron filings near the piece of iron or a nail.
- If not, continue the process again until it gets magnetized.
By this method, we can convert an iron nail, a needle or a blade into a magnet.
Own magnetic compass:
We can make our compass with the help of a magnetized needle.
- Take two styrofoam or thermocol balls and insert the magnetized needle into it as shown in the figure.
- Place the needle set up in a water bowl, such that it floats on the water.
Even when the magnetized needle is placed in the water, the needle will point towards the north-south direction at rest. Instead of styrofoam or thermocol balls, we can use a dry leaf or a cork piece.
A dry leaf floating on water