Understanding Electrical Power and Energy Transfer Equations
Explore definitions, equations, and calculations related to electrical power, energy transfer, and units in this comprehensive lesson sequence. Learn to calculate power, energy, and time through practical examples and worksheets.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
You are allowed to download the files provided on this website for personal or commercial use, subject to the condition that they are used lawfully. All files are the property of their respective owners.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.
E N D
Presentation Transcript
L1 Circuit symbols L11 National Grid L2 Current & charge L3 Potential difference L4 Resistance & Ohm s Law L5 Power & energy L6 Electrical power L7 Current in series & parallel L8 Potential difference in series & parallel L8 Sensing circuits L10 Three pin plug Lesson Sequence Pupils should have been taught to: Pupils will be taught: Students have been taught definitions & equations potential difference. These concepts will be built on during the course of this lesson. Power will be revisited in the electrical power lesson. Future Learning Specification Prior Learning
SciDoc Power & energy Power & energy Last Lesson Last Term Last Year Stretch & Challenge I do We do You do Test I do We do You do Do Now
SciDoc Keywords Learning Objectives Keywords Power Watts Energy Joules Recall the definition of power. Recall the equation for power. Calculate power, energy and time. I do We do You do Test I do We do You do Do Now
The electrical power supplied to an appliance is the energy transferred to the appliance each second. SciDoc Stretch: What is the equation that links energy transferred, charge and potential difference? Give all units. Power has units of Watts. I do We do You do Test I do We do You do LO:
P = E t you must remember this equation! Where: P power in watts (W) E energy in Joules (J) t time in seconds (s) SciDoc Stretch: Sometimes you might see units for power being kWh. This means that a power of 1 kiloWatt is used for 1 hour. How many Joules are there in 1 kWh? I do We do You do Test I do We do You do LO:
SciDoc Worked example Worked example PROBLEM Calculate the energy transferred from the mains when the TV has 3000 kW of power and is turned on for 3 hours. SOLUTION E = P x t P = 3000 kW t = 3 h E = P x t = 3000 x 3 = 9000 kWh The energy transferred from the mains to the TV is 9000 kWh. I do We do You do Test I do We do You do LO:
SciDoc Worksheet Worksheet Complete the worksheet! This is also recapping & retrieving the equation E = Q V All energy units in Joules, not kWh. I do We do You do Test I do We do You do LO:
SciDoc Basic answers Basic answers 1) a) t = E p b) P = E t c) Q = E V d) V = E Q I do We do You do Test I do We do You do LO:
SciDoc Basic answers Basic answers 2. E = P t = 3000 60 = 180,000 J 3. E = Q V = 30 20 = 600 J 4. E = Q V = 30 4 = 120 J 5. E = Q V = 20 6 = 120 J I do We do You do Test I do We do You do LO:
SciDoc Medium answers Medium answers 1. 2. 3. 4. 5. 6. 7. 8. E = P t = 125 2500 = 312,500 J V = E Q = 5000 20 = 250 V t = E P = 36,000 1800 = 20 s Q = E V = 5,000 230 = 21.7 C t = E P = 1300 65 = 20 s Q = E V = 2400 12 = 200 C a) 3500 W a) 7 kW b) 700 W b) 19 kW I do We do You do Test I do We do You do LO:
SciDoc Hard answers Hard answers 1. P = 2000 W, t = 300 s E = P t = 2000 300 = 600,000 J P = E t = 5000 900 = 5.6 W t = E P = 20 60,000 = 0.0003 s Q = E V = 50 1 = 50 C V = E Q = 50,000 3 = 16700 V a) It increases a) It increases 2. 3. 4. 5. 6. 7. b) It increases b) It decreases I do We do You do Test I do We do You do LO:
SciDoc Struggle time! Struggle time! Exam question so exam conditions. You have 6 minutes. I do We do You do Test I do We do You do LO:
SciDoc I do We do You do Test I do We do You do LO:
SciDoc I do We do You do Test I do We do You do LO:
