Static Electricity

If you turn a television on and touch the screen, the screen feels as though it has a film of some sort over it. The tv screen is charged. It has an excess of electron. Many materials accumulate charge in this way. If for example you rub a balloon on your clothes, you may cause electrons to pass from one to the other. If you then hold the balloon close to running tap water, you may cause it to deflect in the way shown below.

Static electricity occurs in nature. Static electricity may build up between the ground and rainclouds. This happens usually when low air pressure causes high winds, causing the same effect as in the example above between your clothes and the balloon. The result is lightning. Static electricity can be dangerous and sometimes precautions must be taken against it. This is especially so at airports when planes are being refuelled. Static electricity may build up between the tanker and the plane for example as the fuel is pumped. With the air full of fuel vapour, any tiny spark could cause an explosion. Hence tanker and plane are earthed, which disallows any build up of static electricity. Closer to home, you may build up static electricity on yourself while driving, if you move about in your seat. When you get out, at a petrol station, the charge you have built up causes a spark and BANG!

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