Year 5/6 a Summer 1 Science Electricity Electric Art
Year 5/6 A Summer 1 Science Electricity – Electric Art
Session 4: Taking a Dimmer Approach…Science curriculum area: Electricity / Content
i. compare and give reasons for variations in how components function, including the brightness of bulbs, the loudness of buzzers and the on/off position of switches
Working Scientifically (UKS2) / i. planning different types of scientific enquiries to answer questions, including recognising and controlling variables where necessary
ii. taking measurements, using a range of scientific equipment, with increasing accuracy and precision
iii. recording data and results of increasing complexity using tables, scatter graphs, bar and line graphs
Teaching Objectives / · To investigate, design and make a dimmer switch (Yr5&6).
· To describe how a dimmer switch affects resistance (Yr5&6).
Other Curriculum areas / D&T Select from and use a wider range of tools and equipment to perform practical tasks accurately; Select from and use a wider range of materials and components, according to their functional properties and aesthetic qualities; Understand and use electrical systems in their products
Teaching Objectives / · To incorporate a dimmer switch into their design (Yr5&6).
· To identify materials and tools required to make a prototype (Yr5&6).
Key Vocabulary: Electrical circuit, complete circuit, components, cell, battery, positive/negative, connect/connection, loose connection, short circuit, bright/dim, switch, conductor, insulator, voltage, current, resistance
Resources
Dimmer switch equipment, diagram for dimmer switch and materials request form / Weblinks https://www.youtube.com/watch?v=hfyknX2W694 - Dimmer switch guidance;
http://www.sciencebuddies.org/blog/2011/12/turn-your-pencil-into-a-dimmer-switch.php
http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel_pre_2011/electricityintheory/voltagecurrentresistancerev4.shtml
Whole Class: Have all switch equipment ready and print off the materials request forms. Look through the dimmer switch guidance in advance so that you know what you are doing! Explain that the NSAA is keen that the lights and buzzers incorporate a dimmer switch for effects. Get chn to remind you what a regular switch is and then ask what a dimmer switch is. Ask chn what they think you need to do to the electricity in a dimmer switch to reduce the brightness in a bulb – remind them how they investigated brightness, volume and speed in Session 2 (they may suggest that you need to put another component in). Get Yr6 chn to remind you what happens to the electricity when it goes into a component (it is resisted) and explain that you need to find a way of essentially reducing and increasing the flow of electricity to create a dimmer switch. Show chn the adapted pencil (see equipment – or a graphite stick should have the same effect) and ask if electricity can flow through this. (Refer back to conductors from Session 1 and double check.) Send chn off in their teams to see if they can investigate/work out how to create a ‘switch’ using the pencil or graphite that will dim a bulb. Give each group a set of equipment (see list) and tell them that will need to use their knowledge of resistance in materials that conduct electricity to help. Give chn 15-20 mins to discuss and try out their ideas. Come back together as a class - hopefully the chn will have come up with some ideas. Get chn to share their ideas and designs and note those that work. Clarify and demonstrate that if the connection (crocodile clip, for example) is moved up and down the graphite the bulb will be brighter at one end than the other. Get chn to explore this themselves, if they haven’t already, and see if they can come up with an explanation in their gps as to why this works. Then send chn off to incorporate this into their design. Explain that today they need to get their design finalised and identify materials that they will need as well as the electrical components required.
Year 5 Dimmer switch - get chn to use the equipment given (they need to use all components) to create a switch that will make the lights, buzzer motor become brighter/dimmer, louder/quieter, faster/slower. Help chn to think about conductive materials resistance and show them how they could control an increase or decrease of electricity that would impact on the component concerned: get them to mark equidistant point on the pencil and test their dimmer light (with a light meter if avail) at various points along the graphite, recording the lux of the bulb in a table & graph. / Year 6 Dimmer switch (ind.) - get chn to use the equipment given (they need to use all components) to create a switch that will make the lights, buzzer and motor become brighter/dimmer, louder/quieter, faster/slower. Encourage chn to use their knowledge of conductive materials and resistance and ask them to think about how they could control an increase or decrease of electricity that would impact on the component concerned. Get chn to mark equidistant point on the pencil and test their dimmer light (with a light meter if avail) at various points along the graphite, recording the lux of the bulb in a table & graph.
Years 5&6 Final design tweaks - Chn to incorporate their ‘dimmer switch’ into their design - encourage them to annotate their current designs rather than re-draw from scratch. Then get each gp to make a final list of the materials, electric components and tools that they will need (see materials request form).
Plenary / Ask chn to share their dimmer switch findings thoughts on how it works – explain that we call it a ‘variable resistor’. Can chn suggest where dimmer switches might prove more useful than on/off switches (to create subtle lighting or alter the volume of a CD, for example)? Show chn the BBC resistance slider (see link) to show what can happen if the resistance is too great (the bulb will go ‘off’) or too low (the bulb will blow, or cause a short circuit). NB chn do not need to understand the ampere or the Ω sign – explain that this is simply a measure of the amount of electricity flow. Explain that in the next session, chn will be making their prototype art installation.
Outcomes / Children will
· Investigate and develop a dimmer switch (with support - Yr5, independently - Yr6)
· Identify materials and tools for their design (Yr5&6)
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