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2 ELECTRICITY Physics

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4 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

5 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.

6 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

7 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

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

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

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