Year 9 Electricity Topic 5 Teacher Booklet PDF

# KS3 Physics Topic 5 - Basic Electricity ## Wallace High School ### Year 9 Physics #### Topic 5 - Basic Electricity - Pupil Name - End of topic assessment % - Teacher Name - Class Average #### My areas of strength were: - End of topic feedback #### TEACHER BOOKLET #### My areas for improvement ar...

# KS3 Physics Topic 5 - Basic Electricity ## Wallace High School ### Year 9 Physics #### Topic 5 - Basic Electricity - Pupil Name - End of topic assessment % - Teacher Name - Class Average #### My areas of strength were: - End of topic feedback #### TEACHER BOOKLET #### My areas for improvement are: #### I can improve my examination technique by remembering to: - Teacher Initials: ## Experiences and outcomes - I have used a range of resources to investigate electricity and know a little of the history of its discovery. - By applying my knowledge of electricity I can predict how a circuit will function, including electromagnets. - I can evaluate my work; I can adapt and improve, where appropriate through trial and error or by using feedback. ## Prior Knowledge - Learners will have some knowledge of charge from atomic structure and friction from Yr8 forces. - They will have possibly made circuits in technology and have a common knowledge of electricity from home use. ## Learning Intentions | Learning Intentions | Success Criteria | Possible Evidence | |---|---|---| | Know that 'electricity' comes from a build up of charge which we call "static electricity". | You are able to explain how rubbing materials can create static electricity and how a Van do Graff works and discharges. | Practical experiences with rods and dusters and class demo/practical with the Van do Graff. Workbook notes and iPad Quizzes. | | Know that when charge moves through a wire at a steady rate we call it "current electricity". | You can build simple circuits to include a battery, switch and bulb. You know the differences between conductors and insulators. | Practical experiences testing materials and building simple conducting circuits with a bulb and various materials. Notes, diagrams and questions in workbook. | | Understand that a circuit must be complete and made of conductors (not insulators) for electricity to flow. | You are able to identify, draw and build a simple series and parallel circuit with 2 bulbs. | Practical work making circuits and testing the possible outcomes. Workbook notes and tasks | | Know there are two main types of circuit, series and parallel. | You can predict and describe the outcome for various circuits in terms of bulb brightness and ON/OFF. | iPad quizzes | | Understand how the circuit type affects bulb brightness and current flow. | | | | Know how to make an electromagnet and test its strength (number of coils). | You know how to construct an electromagnet and use it to lift paperclips. | Practical making and testing of a simple iron nail electromagnet. Workbook notes, results and conclusion (graph) | ## New Words and Spellings: - By the end of this unit you should know the meaning of the words indicated below and be able to spell all the words listed: | Term | Definition | |---|---| | Charge | Physical property of matter due to electrons and protons - + or - | | Discharge | An object loses or gains electrons to become uncharged or neutral. | | Conductor | A substance that conducts electricity allows charge to flow. | | Insulator | A substance that does not allow electricity through. | | Current | A flow of electricity due to moving charged particles | | Series circuit | A circuit that is a chain of components | | Parallel circuit | A Circuit with branches that divides the electricity | | Electromagnet | A iron core with coils of wire around it that makes a magnet when current flows. | # Lesson 1 - Static Electricity - By the end of this lesson you should be able to: - Know how to create static electricity - Explain how it builds up and can be discharged - Static electricity is all around us, sometimes funny and obvious, as when it makes your hair stand on end, tiny lightning zaps whenever you touch door knobs or warm blankets fresh from the clothes dryer. Sometimes hidden and useful, as when harnessed by the electronics in your mobile phone. - Static electricity is one of the oldest scientific phenomena people observed and described. Greek philosopher Thales of Miletus in the sixth century B.C. noted that if amber was rubbed hard enough, small dust particles will start sticking to it. - It took almost 2,000 more years before the English word "electricity" was first coined, based on the Latin "electricus," meaning "like amber." Some of the most famous experiments were conducted by Benjamin Franklin in his quest to understand the underlying mechanism of electricity. People quickly recognized electricity's potential usefulness. Of course, in the 18th century people mostly made use of static electricity in magic tricks and other performances. ## Question - One of Franklin's most famous experiments involved a kite and lightning. What did he do? - He demonstrated the connection between lightning and electricity by flying a kite in a storm. He didn't actually get electrocuted. - Some fun tricks with Static: https://www.youtube.com/watch?v=ViZNgU-Yt-Y # The Van de Graff Generator - To understand how the generator works it is important to understand the structure of the atom. | Sub-atomic particle | Location | Charge | |---|---|---| | Proton | Nucleus | + | | Neutron | Nucleus | Neutral | | Electron | Orbital shells | - | ## How the Van de Graff works. - As the motor turns the bottom roller (1), the belt rubs on the brush (2) at the top. Electrons are transferred from the brush and the metal dome (1) to the belt and travel down (5) where they are transferred off the belt by the lower brush (7). The belt is now equally charged with positive and negative charges (4). - When the charged dome is discharged, electrons flow back onto it from a metal sphere (8) creating a spark (9). - Your teacher will show you the following Van de Graff demonstrations, describe what is happening in each. - https://www.youtube.com/watch?v=Gf6EbRmYlml 1. Sparks / Lightning bolts - This is when enough Charge builds up between 2 points. Eventually the electrons jump across the air gap discharge the + dome. Each hair becomes positive, Positive Charges repel hairs try to get away from their each other So all the hairs try to get away from their neighbors. 2. Hair standing on end - A student needs to be charged up! A 2nd student points their finger at the top of the bunsen while the charged student does the same from the other side - the discharge spark will light the gas! 3. Lighting a Bunsen Burner with a finger! # Lesson 2 - Current Electricity - *Download the App Physics Lab AR from Self Service* - By the end of this lesson you should be able to: - Understand charge flowing through a wire at a steady rate is "current electricity" - Know how to draw simple circuits - Be able to test and identify materials as conductors or insulators and know why. ## Circuit Symbols - We use circuit symbols to represent the different parts in an electrical circuit. Straight lines are drawn to represent the wires. ___ - **open** - **'long' 'Short+fat'** - closed - **switch** - **cell** - **battery** - **lamp** ___ ## Cells and batteries - A conventional battery - like the ones you put in a remote or a clock - are called a cell in physics. If there are two or more cells together then it is called a battery. ## Circuit diagrams - The idea of a circuit diagram is to use circuit symbols instead of drawing each component in the circuit. Always try to make the wires straight lines, and don't be tempted to make them wiggly. The whole point is to make it easier to see what is connected to what. Here you can see how the symbols for a cell (not a battery!) and a lamp look in a circuit diagram. - Draw the circuit symbols first, and then add all the wires. Use a ruler and don't let the wires cross each other. # Experiment - Making a Simple Circuit and testing for conductivity - Apparatus: - 2 cells - switch - light bulb - 3 leads - 2 crocodile clips - Sample materials - Safety: - Care with circuit - only 2 cells!! - Keep away from water. - Method: 1. Set up the apparatus as shown in the diagram 2. Use the circuit symbols to draw a circuit diagram for the simple circuit you have made 3. Press the switch does the bulb light up? ...yes 4. Replace the switch with a crocodile clip on the end of each wire. 5. Take a sample of material and connect it between the crocodile clips. 6. Observe what happens to the bulb and record in the table below. | Material | Did the Bulb light up? | Conductor or Insulator? | |---|---|---| | Wood | No | Insulator | | Copper wire | Yes | Conductor | | Polythene rod | No | Insulator | | Glass rod | No | Insulator | | Aluminium foil | Yes | Conductor | | Iron nail | Yes | C | | Magnesium ribbon | Yes | C | | Lead foil | Yes | C | | Graphite rod | Yes | C | | Zinc sheet | Yes | C | ## Conclusion - Most of the materials which allowed the current to flow through them (conductors ) all happen to be metals. - This is because metals contain free electrons (delocalized) which are able to move through the material, providing a flow of charge (electric current) and the bulb lights up / ON. - The materials which do not allow current to flow through them (insulators ) are all non-metals. They lack free electrons to conduct electricity so the bulb remains OFF. - There is an exception to the above rule about non-metals all being insulators, what is it? ... graphite # Lesson 3 - Types of Circuit - Series and Parallel - By the end of this lesson you should be able to: - Know there are two main types of circuit called series and parallel. - Be able to identify and build both types. - Be able to predict and test how both circuits affect bulb brightness. - There are many ways to connect components together and as long as the circuit is complete, i.e. all conducting materials and a continuous path between the two terminals of the cell/battery the electricity will flow. There are more efficient and effect ways to make circuits and they are all based on two basic designs - SERIES or PARALLEL. ## Experiment - Series and Parallel Circuits - Apparatus: - 2 Cells - 2 bulbs - 1 switch - 7 wires - Safety: - Care with circuits - 2 cells only! - Use the apparatus and the diagrams to make the different circuits: ### Circuit 1 - **Series Circuit** - Close the switch and observe the brightness of the bulbs... medium/ low brightness ### Circuit 2 - Add another cell. This needs to be added correctly - if you look at a cell it has two end, a negative and positive end. The positive end of one cell must always be attached to the negative end of another cell. - Close the switch. What do you notice about the brightness of the bulbs now? Brighter bulbs - Unscrew one of the bulbs and note what happens to the other one. They both go out. - The bulbs in circuits 1 and 2 are described as being arranged in "Series". There is ONE loop only ### Circuit 3 - Remove the second cell and rearrange the bulbs as shown in circuit 3 below. - Close the switch. What do you notice about the brightness of the bulbs? Equally bright - Unscrew one of the bulbs and note what happens to the other. The other one stays on. - The bulbs in this circuit are described as being in "Parallel". There are multiple loops for the electricity to follow. # Circuit 1 - Only when the switch is closed and the circuit becomes COMPLETE (known as "closed") will the bulbs light. - Each bulb has the SAME brightness. ## Circuit 2 - Adding an extra cell makes each of the bulbs shine BRIGHTER. - Unscrewing one of the bulbs causes the other bulb to GO OUT. (an "open" circuit) ## Circuit 3 - The bulbs have EQUAL brightness. - Unscrewing one bulb DOES NOT cause the other to go out. ## More complicated circuits - From what you have learnt about series and parallel circuits so far, rearrange circuit 3 so that one bulb is lit constantly and the other only lights when the switch is closed. Draw the circuit diagram for this and test it out. # Homework 1 - Circuit Diagrams 1. Draw a circuit diagram showing two cells, one switch and one bulb. 2. Draw a circuit diagram for a circuit containing three cells and two bulbs connected in series. 3. Draw a circuit diagram for a circuit containing one cell, one switch and three bulbs connected in parallel. 4. Draw a circuit diagram for a circuit containing one cell, two switches controlling two bulbs in parallel. 5. Draw a circuit diagram for a circuit containing two switches, two cells and three bulbs connected in series and parallel. 1st switch turns the whole circuit off 2nd switch turns 1 bulb off. # Lesson 4 - Electromagnets - By the end of this lesson you should be able to: - Know how to make an electromagnet and test its strength (number of coils). - Test your prior knowledge from Yr8 on the next activity... ## Electromagnets - When an electric current flows in a wire it creates a magnetic field around the wire. - By winding the wire into a coil we can strengthen the magnetic field. Electromagnets are made from coils like this. ## The magnetic field of an electromagnet - The magnetic field around an electromagnet is just the same as the one around a bar magnet. It can, however, be reversed by turning the battery around. - Unlike bar magnets, which are permanent magnets, the magnetism of electromagnets can be turned on and off just by closing or opening the switch. ## Experiment - Making and testing an Electromagnet - Apparatus: - One large iron nail - 50cm insulated wire - Cells. - crocodile clips - paper clips - Safety: - Care with circuits - 2 cells only! - Hot wires. - Nipped by croc clips - Method: 1. Make the electromagnet as shown with 10 coils of wire. 2. Attach the wire to the leads using the crocodile clips and then the cells. 3. Hold the nail vertically and pick up as many paperclips as possible. You may want to clamp it in position. 4. Record how many paper clips the electromagnet has attracted or weight them if they are different sizes. 5. Disconnect the cells. 6. Increase the number of coils to by 10 to 20 and repeat the experiment. 7. Continue to increase the coils by 10 up to 50 coils in total. ## Results | Number of coils | Number of paperclips | Mass of paperclips(g) | |---|---|---| | 10 | 3 | 10 | | 20 | 13 | 19 | | 30 | 18 | 29 | | 40 | 20 | 42 | | 50 | 23 | 50 | ## Conclusion - As the number of coils increases so does the Strength of the electromagnet. It is proportional (constant ratio) ## Making an electromagnet stronger - We can make an electromagnet stronger by doing these things: - wrapping the coil around an iron core. - adding more turns to the coil - increasing the current flowing through the coil. ## Applications of an Electromagnet - What are the advantages of an electromagnet over a permanent magnet? - You can turn an electromagnet on and off. - They can be made very powerful. - Many objects around you contain electromagnets. They are found in electric motors and loudspeakers. Very large and powerful electromagnets are used as lifting systems in scrap yards to pick up, then drop, old cars and other scrap iron and steel. They are also found in door and gate locking systems and recycling centres. - The Electric bell (https://www.youtube.com/watch?v=qMB5nQmB82M) - Electric bells like the ones used in most schools also contain an electromagnet. - Your teacher will demonstrate how it works. Use the diagram and what you know about electromagnets to explain how. - The circuit completes when the switch is pressed. Current flows and the electromagnet twn on. The soft iron armature is attracted to the magnets & the hammer hits the bell. The contact break and the magnets twn off, the "hammer Springs back and the contact is re-made ... REPEAT ! # Homework - Electromagnets 1. Rose wants to see the effect of increasing the amount of current on the strength of an electromagnet. - a) Predict what she will see as she increases the number of cells. Give a scientific reason. - b) Draw and label the assembled equipment she will need for the experiment. - c) What factors will she need to control to make it a fair test? - d) What other factor could she investigate and how would she have to alter her experiment to ensure a fair test. # Electromagnetism Summary Wordsearch - S U C 0 B A L T C P 1 N D U C E D D A 0 L L A T T R A C T L R 1 C U R R E N T E E K F E L D L P E R M A N E N T P E S 0 L E N 0 1 D 0 L A N 1 C K E L X N ## Questions 1. What is the strongest part of a bar magnet? 2. What is the area around a magnet called? 3. What do two 'like' poles do? 4. What type of magnet produces its own magnetic field? 5. What is a coil of current carrying wire called? 6. Which magnetic element has the symbol Co? 7. What type of magnetism is lost when the current is switched off? 8. What effect does a magnet have on magnetic material? 9. What metal is used as the core of an electromagnet? 10. What has to flow in a wire to create a magnetic field around it? 11. Which magnetic element has the symbol Ni? 12. What type of poles attract each other? # Topic Evaluation - In the context of how science works, students should be able to: - I know that 'electricity' comes from a build-up of charge which we call "static electricity". - I am able to explain it in terms of movement of electrons. - I know that when charge moves through a wire at a steady rate we call it "current electricity". - I understand that a circuit must be complete and made of conductors (not insulators) for electricity to flow. - I can explain the difference between conductors and insulators in terms of electrons. - I know there are two main types of circuit, series and parallel. - I can draw series and parallel circuits. - I understand how the circuit type affects bulb brightness and current flow. - I can predict will happen to bulbs in a series or parallel circuit. - I know how to make an electromagnet and can design an experiment to test its strength. _**Now complete the review at the front of this workbook.**_ _On the skills diagram, traffic light any areas of this unit where you have developed any of these skills._ ___ - Literacy - ICT - Numeracy - Self-Management - Skills & Capabilities - Decision Making - Problem Solving - Working with Others - Managing Information