2. ELECTRICITY Physics

3. EDD 5161F (Gp 4) Lee Wing Ying (97096920) Chan Pui Ching (97038100) Wong Lai Yuk (97029290)

4. Target audience:F.3 Basic knowledge: Unit of electricity Simple Calculation about Electricity

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6. Electrical Power Electrical Power Power = Energy change / time unit of power: Watt (W) unit of energy: Joule (J) unit of time: second (s) 1W = 1Js -1

7. Unit of Electricity Unit of Electricity - The energy consumed in household appliances is measured in kilowatt-hours (kWh) is measured in kilowatt-hours (kWh) - One kilowatt-hour is the amount of energy that is used by a 1000 W appliance in one hour. that is used by a 1000 W appliance in one hour.

8. The total cost of electricity consumption in June 0.12 0.28 0.4 12 0.084 0.196 0.28 8.4 12.8 384 8.96 268.8

9. Electricity Bill Chan Tai Man 13 Nathan Road Kowloon 85467-253-07 Chan Tai Man 13 Nathan Road Kowloon 28-04-98 共日用電量 由 至 59 01-03-9828-04-98 06-05-98

10. Kilowatt-hour meter Kilowatt-hour meter When the mains cable enters the home, it is connected through a fuse to a kilowatt-hour meter.

11. Main Circuit Main Circuit Live wire ( 火線 ) This carries the alternating current to the appliance This carries the alternating current to the appliance. Neutral wire ( 中線 ) This carries the alternating current to the appliance This carries the alternating current to the appliance. It connects the metal body of the appliance to the earth. If a live wire becomes loose and touches the metal body, a large current flows to earth. The person does not get an electric shock. Earth wire ( 地線 )

12. Standard Socket and Plug WireSymbolColour LiveLbrown NeutralNblue EarthEgreen and yellow

13. Wiring in a 3-pin plug The live wire is joined to the live pin through a cartridge fuse. The other wires are screwed directly to their corresponding pins.fuse E N L

14. Appliances with an earth and a fuse FUSE Y X Z X is Y is Z is Neutral Live Earth

15. Through a faulty kettle with earthing

16. BOMB Through a faulty kettle without fusing and earthing

17. The ring circuit Earth Live Neutral

18. Circuit in our home Neutral Live

19. Neutral Live Example:

20. Neutral Live Example:

21. http://www.hec.com.hk Hong Kong Electric Holdings Ltd. China Light & Power Co. Ltd. http://www.chinalightandpower.com.hk Two Electrical Suppliers in Hong Kong:

22. THE END