Zusammenfassung der Ressource
The usefulness of electrical appliances p1.3
- energy and appliances
- energy transfers from a power station to schools,homes and industry as an electrical current
- power is how much electrical energy,in joules,is transformed per second,into another energy..
- the higher the power the more current it needs .
- power is measured in WATTS (W)
- one watt is the same as 1 joule per second
- example
- 220 jouels and 2 seconds = (p) power= energy divided by time (in seconds)=220 divided by 2 =110w
- The cost of
electricity
- where 1kw=1000W.the power rating of an appliance is shown on a label
- the unit of electrical cost is the Kilowatt hour (kwh)
- E=P*T
- ENERGY TRANSFERED=POWER*TIME
- TOTAL COST O ELECTRICAL APPLIANCE =KWH*COST PER UNIT IN PENCE
- TOTAL=NUMBER OF KILOWATT-HOURS *COST PER KILOWATT-HOUR