Fun with Magnets Notes

INTRODUCTION

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.

1. 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.
 

MAGNETISM

It’s a natural phenomenon that causes

1. magnets or magnetic substances to attract other magnetic substances towards itself (property of attraction)

2. magnets or magnetic substances to align itself in one particular direction when suspended freely (directional property)