1. Paying for Electricity L.O. You will be able to define the unit of Power You will be able to recall that energy from the mains is measured in kWh (kilowatt-hours) You will be able to calculate the power and energy used and the cost of that that energy

2. Starter Re-cap Define these terms 1Primary Coil 2Secondary Coil 3Slip Rings

3. Keywords activity 1Look at your cards, there are six Keywords and 12 definitions. Match each word to 2 definitions. 2Lay them out as you think they ought to be 3Let’s check 4Stick them into your book

4. How much Energy? 1What is the power rating of a toaster that uses 68,000 Joules in 40 seconds? 2What is the power rating of a electric blanket that uses 450,000 J in 7,200 seconds? 3What is the power rating of a food mixer that uses 40,000 J in 2 min 4What is the power rating of a TV that uses 90 kJ while watching Eastenders? 1How much energy is used by a kettle with a power rating of 1200 W in 90 seconds? 2How much energy is used by a electric fire with a power rating of 2000 W in 4 hours? 3How long would it take a cooker with a power rating of 1800 W to use 600,000 Joules? You use about 7,500,000 Joules a day, or 5,208 Joules a min or 87 Joules a second! Q If the toaster from Q1 was on all day how much energy would it use?

5. How much power? You can work out the power of a device from the Current and the Voltage 1A laptop uses 19 Volts which is supplied by 3.5 A current. What is the power of the laptop? 2A Hoover uses 230 Volts which is supplied by 9 A current. What is the power of the Hoover? 3A oven uses 230 Volts which is supplied by 12 A current. What is the power of the oven? 1A radio uses a 9V battery and has a power rating of 18 W. How much current is the radio drawing (Using)? 2A toastie maker uses a 230V and has a power rating of 1800 W. How much current is it drawing (Using)? 3A radio has a power rating of 18 and the current is 2A. What is the voltage of the supply? 4A toastie maker has a power rating of 1800 W and a current of 7.83A. What is the Voltage?

6. How much does it cost? (Other than The Earth!) 1Electricity costs 15p per kWh how much does it cost to run a TV with a power rating of 25W for the duration of Top Gear? 2Electricity costs 7p per kWh. How much does it cost to cook a roast dinner (2 hours cooking time) if your oven has a power rating 2000W? 3You are having a party that will last 3 hours. Your stereo has a power rating of 70W. If electricity costs 10p per kWh, how much money will your parents spend? 4Now do questions 4 and 5 from page 263. 1What is the cost if the P = 400 W, t = 3hrs and cost per kWh = 9p? 2Cost if P = 500 W, t = 2hrs and cost per kWh = 20p 3Cost if P = 2000 W, t = 4hrs and cost per kWh = 8p 4Cost if P = 1 kW, t = 2hrs and cost per kWh = 15p 5Cost if P = 900W, t = 30 min and cost per kWh = 7p

7. Smart Meters, why? Look at Q 7 Page 263 Discuss your ideas with your partner Make notes on your under these headings Work to be done / Ease of use / Disadvantages (What don’t you know)? Let’s discuss Make notes on your work Now try to answer Q7 as fully as possible Remember we are looking for 6 marks so use try to use the vocabulary and think about spelling and punctuation

8. Plenary