2. Static Electricity Chapter 50

3. What is electricity? Electricity is a form of energy and it may be converted to other forms. It can cause a motor to turn and a kettle to heat up

6. Static Electricity. Static electricity involves charges that remain at rest on an object. When two objects are rubbed together, electrons get transferred from one object to the other. Some substances like polythene and perspex (good insulators) do not allow these electrons to flow out so they build up an electrical charge called static electricity.

7. Polythene Rod The polythene rod becomes negatively charged. This is because electrons move from the cloth on to the polythene rod.

8. Perspex Rod. Perspex If a perspex rod is rubbed with a woolen cloth The perspex rod becomes positively charged. This is because electrons move from the rod on to the cloth.

9. Negative and positive charge A body is negatively charged if it gains electrons. A body is positively charged if it loses electrons. Note: Only the electrons can move

10. To investigate the force between charged objects. Set up apparatus as shown in diagram. Bring a charged polythene rod(-) close to but not touching a charged perspex(+) rod. Result The rods are attracted to each other. Like charges repel; Unlike charges attract.

12. What happens if the balloon on the left is let go? Explain your answer.

13. Effects of Static electricity Van Der Graff generator Hair raising moment

14. Useful effects of static electricity. Static electricity can be used in: Photocopier Spray painting Pesticides Removes soot from chimneys

15. Nuisance effects of static Attract Dust Electric shock from car Dangerous effects Inflammable liquids can ignite causing fire Thunder and lightning

16. Damage to a church caused by lightning

17. Earthing Earthing occurs when a charged object loses it’s charge to the earth. A lightning conductor protects buildings because it provides an easy route for the lightning to get to earth.