Spark image

Important applications and effects of static electricity

1. A charged mesh in a chimney acts as an electrostatic dust collector, cleaning the smoke.

2. Paint sprays can be charged and the object they are spraying earthed to attract the paint towards it.

3. Vinyl records have to be cleaned to remove the static charge that builds upon their surface.

4. People thought that static electricity was the cause of car sickness until it was remembered that a static charge can only be on the outside of a hollow conductor like a car.

5. Photocopiers work by a charged sheet attracting fine carbon powder to make the image

6. It can be shown that a water molecule is polar - that is it has one positive end and one negative one. A stream of water can be deflected by a charged polythene rod placed near it.

7. Capacitors
A capacitor stores static charge in its simplest form it is two plates that are separated by air. More charge can be stored by increasing the area of the plates, putting them closer together or using another insulator instead of air. In a practical capacitor the plates are usually rolled up with paper insulation in between them. In a radio receiver a variable capacitor with moveable plates is used as the tuner.

8. People must take care when emptying oil tankers and refueling aircraft to avoid a build up of static charge due to friction that could make a spark and result in an explosion.

9. Lightning see separate page on lightning.


© Keith Gibbs 2020