As a child you would have played with small magnets. It seems like magic, when that little mysterious thing, called magnet, can pick up needles or stapler-pins and hold them indefinitely. But magnets are far from being a just a toy to play with. Magnets are essential part of many modern day machines, tools and measuring instruments/devices.
We all are familiar with magnetic compass that helps mariner find direction and maintain their course at sea. Door of a fridge when kept slightly open, pulls by itself and shuts. Doors of cupboard & almirah also close by such magnetic locking mechanism. Flaps of handbag & leather-diary click shut as they have magnet. When you hold a phone receiver close to your ear, a magnet records the vibrations set up by the voice of the person talking at the other end. Magnets and magnetism finds lot of application in many industrial use.
Stickers on doors of refrigerator/ almirah/cupboard attached to iron surface with magnet fitted at the back
DISCOVERY OF MAGNETISM
Phenomenon of magnetism is known to humankind for many centuries. Chinese sailors used magnets for navigation. It is believed that “Thales”, Greek philosopher (sixth century B.C.), was the first to observe phenomenon of magnetism in lodestone (for their directional property which is when suspended rotates in certain geographical direction).
After his discovery, lodestone (leading stone) was often mentioned in many ancient writings. It was given the name “magnet” after Magnesia, a district in the Asia Minor where large magnetic deposits are found.
Why the name Lodestone:
Lodestone stands for leading stone which is attributed to directional property of magnet as they orient themselves in geographical north-south direction when suspended freely.
It’s a natural phenomenon that causes
magnets or magnetic substances to attract other magnetic substances towards itself (property of attraction)
magnets or magnetic substances to align itself in one particular direction when suspended freely (directional property)
Magnets are made of materials that possess attractive property and directional property.
Attracts objects made of iron and nickel or their mixtures/alloys
Iron fillings attracted to the bar magnet
Magnet attracting pieces of iron nails
When suspended freely, magnet orients itself in one particular geographical directionRead More...
POLES OF A MAGNET
Every magnet has two poles, North pole (N) and South pole (S). The areas of greatest magnetic force inside the magnet are called magnetic poles.
Rules of Magnet:
Like poles repel each other. North pole of a magnet will repel north pole of another magnet. Similarly, south pole of a magnet will repel south pole of another magnet.
Unlike poles attract each other. North pole of a magnet will attract south pole of another magnet.