1. 3.4 Domestic electricity slides
D Wilson

2. Lesson 1 -Power

3. Starter Rank these in power used.
Electric clock
Cd player

4. Starter Answer Appliance Power rating (watts) Kettle 2000 Dishwasher
1500
Iron
1000
Washing machine
500
Blender
300
laptop
200
Cd player 30
Electric clock 1

5. Watts to kilowatts REMEMBER From watts to kilowatts you ÷ 1000
400wtts = 400/1000 kilowatts = 0.4kW
From kilowatts to watts you x 1000
5kW = 5 X 1000 watts = 5000 watts

6. Power Energy transferred (j) = Power (W) x time (s) E = P x t
Power = Energy transferred / time
P = E / t
Watts = joules / second

7. What uses the most energy in a week?
Appliance
Power rating (watts)
Time used for over a week
Kettle
2000
10 minutes
Dishwasher
1500
60 minutes
Iron
1000
300 seconds
Washing machine
500
180 minutes
Blender
300
100 seconds
laptop
200
400 minutes
Cd player 30
4 minutes
Electric clock 1
24 hours each day

8. Lesson 1 – Reflection Convert them to kW
Appliance
Power rating (watts) (kW)
kettle
2000
Washing machine
500
laptop
200
dishwasher
1500
Electric clock 1
Iron
1000
Cd player 30
Blender
300

9. Lesson 2- Using electrical energy

10. Lesson 2 – Using electrical energy

11. Electric bills