Magnetism

In ancient times Greece people found a rock that attracts iron, nickel and cobalt. They call them as “magnet “and magnetism comes from here. These rocks were used later by Chinese people to make compasses. Later scientists found that, magnets have always two poles different from electricity. Magnets have two ends or faces called “poles” where the magnetic effect is highest. In last unit we saw that there is again two polarities in electricity, “-“charges and “+” charges. Electricity can exist as monopole but magnetism exists always in dipoles North Pole (represented by N) and South Pole (represented by S). If you break the rock into pieces you get small magnets and each magnet also has two poles N and S.
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