COST OF ELECTRICAL POWER

1. cost of electrical
power
MISS GLADNESS'S CLASS

2. Natural Science !
Welcome to

3. LIGHTS ON!!
LIGHTS ON!!
LIGHTS ON!!

4. What do you know about
electricity???

5. learning outcomes:.
Learners should be able to understand and define
concepts related to this topic.
Learners should be able to calculate the cost of power.
Learners must be able to list ways of saving electricity.

6. What is
electricity?

7. ELECTRICITY IS THE RATE AT WHICH ENERGY IS
PROVIDED.
THERE ARE UNITS PROVIDED FOR TERMS THAT ARE
RELATED TO ELECTRICITY:
Energy is the capacity for doing work.

8. ENERGY -
JOULES (J)
TIME-SECONDS(S)
POWER(TOEE)-WATT(W)
THE AMOUNT OF ENERFY
TRANSFERRED -
KILOWATTS(kW)

9. In different households an electricity meter is used to measure
the energy usage.
Consumers of electricity often pay for the number of
kilowatts(the amount of energy transferred) they used for a
specific period.
The unit in which electricity is sold is in kWh.
The below formulas can be used to do calculations:
Energy use= Kilowatt X Number of hours used.
Power=W-energy (J)/t- time(s).

10. IMPORTANT CONVERSIONS.
Cents to Rands. (Division)
100c=R1
thus:
143c/R100=?
Rands to cents (multiply).
R1=100c
thus:
R19x100c=?

11. Important conversions cont...
Joules to KIlojoules(Multiplication).
1 Joule=0,001kJ
thus:
33000JX0,001kJ=?
Kilojoules to joules (Division).
0,001kj=1 Joule
thus:
33Kj x 0,001=?

12. Important converstions cont...
Watts(W) to kiloWatts(kW)(Division).
1000W=1kW
Thus:
284000W/1000=?
kiloWatts to Watts(Multiplication).
1kW=1000W
Thus:
284kW x 1000=?

13. Important conversions continued...
1 minute=60 seconds
1 hour=60 minutes
thus
in order to change seconds to minutes we divide
the number of seconds by 60.
and in order t change minutes to seconds we
multiply the number of minutes by 60.
e.g 120s to minutes = 120/60=?
2 minutes to seconds = 2x60=?

14. IMPORTANT CONVERSIONS CONTINUED....
HOURS TO MINUTES
In order to convert minutes to hours we divide
minutes by 60.
Minutes to hours.
in order to change hours to minutes we multiple the
hours by 60.
N:B Ex 22 question 1.4

15. HOW DO YOU THINK WE
CAN SAVE ELECTRICITY?

16. Using solar panels to covert solar energy into
electrical energy.
Using flauroscent lightbulbs/ energy saving lightbulbs
to save energy.
what is the difference between flauroscent light
bulbs and normal light bulbs?
questions???
solar panels can be used for geysers,pumps and electric
motors.

17. LIGHTS OUT!!
LIGHTS OUT!!

18. The end!!
Thank you for attending.