1. Electricity bills Assume cost per unit = 10p 1,000W = 1 KW
Cost for one hour = Number of watts x cost per unit
1,000
Assume cost per unit = 10p

2. Appliance
Watts (W)
Cost per hour
Speaker 10
10/1000 x10p = 0.1p
Light bulb 60
60/1000 x 10p = 0.6p
Light tube
125
125/1000 x 10p =1.25p
Power Drill
720
7.2p
Kettle
2750
27.5p
Mixer
240
2.4p
Record turntable
0.1p TV
220
2.2p
Fire
2400
24p
Tape recorder 6
0.06p

3. Reading an Electric meter

4. 3 Paying for Electricity
Units used
Night unit Cost £
Day unit cost £ 1
618
22.25
57.17 2
1217
43.81
112.57 3
1566
56.38
144.86 4
3293
118.55
304.60 5
1313
47.27
121.45
Look at dial meter and read pointer complete Q 6 - Q 12

5. Paying for Electricity
Read about Present reading and previous reading
Complete Q 2 - 5

6. Counting the cost 1kW = 1,000W Energy used = Power rating x time
Power (rating) kW
Time (h)
Energy kWh

7. Assume 24 hours in a day a)£4.32 72 kWh 24 kWh 2.4 kWh b) £1.44
c) 14 pence
4 hours
20 hours
1.5 kW
2.5 kW
180 units
£100.80
Q1 – 8 Page 2
Extension work = page 72 & 73 Q 1-3 std grade Sci text book

8. Page 43 Science in View Counting the cost – Answer Q 1 - 3
Energy Cost examples Q1 - 7 Card 4G
Cost of Energy in the Home
Page 83 – 85 Science FrameworkQ2, 3 4 Page 89 & 90