explain with the help of a labelled diagram the construction in the working of a magnetic compass
Answer (1)
Making a simple magnetic compass involves creating a freely rotating magnetized needle that aligns itself with the Earth's magnetic field.Magnetize a steel needle, and provide a way for it to pivot with very low friction (like floating it or balancing it carefully). It will then align itself with the Earth's magnetic field, acting as a compass.How to Create a Magnetic CompassObtain a Needle - Find a small, lightweight piece of ferrous metal (iron or steel) that can be easily magnetized, like a sewing needle or a paperclip straightened out.Magnetize the Needle - This is the crucial step, make sure you do it right. Take a strong permanent magnet (like a bar magnet or a neodymium magnet).Stroke the needle repeatedly with one pole (either north or south) of the magnet. It's important to stroke in the same direction each time, lifting the magnet away from the needle at the end of each stroke before starting the next one. Do this about 30-50 times.This process aligns the magnetic domains within the needle, turning it into a weak magnet with its own north and south poles.Create a Pivot Point (Low Friction) - The magnetized needle needs to rotate freely with minimal friction. Here are a few ways:Floating - Carefully place the magnetized needle onto a small piece of cork, styrofoam, or a leaf, and float this in a non-metallic bowl (like glass or plastic) filled with water. The water surface acts as a low-friction pivot.Hanging - Tie a fine thread (like silk) to the exact center of the needle (you might need to find the balance point carefully) and hang it so it can spin horizontally.Balancing - Balance the needle carefully on the tip of a sharp pencil or another pointed object. This requires good balance.Allow Alignment - Once the needle is free to rotate horizontally, keep it away from other magnets or large metal objects. It will slowly swing back and forth and eventually settle, aligning itself with the Earth's magnetic field lines. One end will point towards the Earth's magnetic north pole (which is geographically near the North Pole), and the other end will point towards the magnetic south pole.Casing and Markings - For a more permanent compass, you would mount the pivot and needle inside a protective casing. A circular card (compass rose) marked with North (N), South (S), East (E), and West (W) directions would be placed underneath the needle. You would need to know the actual North direction (using the sun, stars, or another compass) to correctly orient the card initially when fixing it relative to the casing.
