MC Science_Activity Book with ans_Stage 6_C05

5 More About Electricity Worksheet Can These Materials Conduct Electricity? Aims: • To find out which materials are electrical conductors • To classify materials as electrical conductors and insulators Skills: Observing, communicating, inferring, classifying What you need: Batteries, battery holder, bulb, bulb holder, wires with crocodile clips, aluminium foil, copper wire, rubber band, pencil lead and four other items from pupils pencil case, such as wooden pencil, plastic ruler, steel paper clip and iron staple Work in groups Set up this electric circuit to make a circuit tester battery wire bulb point X point Y Connect a piece of aluminium foil to points X and Y of the circuit tester Observe whether the lamp or bulb in the circuit tester lights up Record your observations in the table on the next page More About Electricity 59 Repeat steps 3 and 4 with a copper wire, a rubber band, a pencil lead and four objects made of different materials from your pencil case, such as wooden pencil, plastic ruler, steel paper clip and iron staple, one at a time Record your observations below Object What material is it made of? Is the material a metal? Does the bulb light up? Is the material an electrical conductor or insulator? aluminium foil aluminium yes yes electrical conductor copper wire copper yes yes electrical conductor rubber band rubber no no electrical insulator pencil lead graphite no yes electrical conductor (Answer varies.) 60 Chapter Based on your observations, classify the materials of the objects into two groups, electrical conductors and insulators Electrical conductors Electrical insulators aluminium rubber copper graphite (Answer varies.) Are the metals electrical conductors or insulators? The metals are electrical conductors Are the materials that are not metals electrical conductors or insulators? The materials that are not metals are electrical insulators, except for graphite, which is an electrical conductor More About Electricity 61 Worksheet Do Different Metals Conduct Electricity Equally Well? Aim: To find out whether different metals conduct electricity equally well Skills: Observing, communicating, analysing, inferring, identifying What you need: Multimeter, 1 m long copper wire of about 1 mm in diameter, 1 m long iron wire of about 1 mm in diameter, battery, battery holder, wires with crocodile clips Your teacher will use a multimeter to measure the amount of electric current flowing through a copper wire He or she will tap the black probe of the multimeter on one end of the copper wire battery multimeter black probe copper wire Do not touch the wires or any part of the electric circuit when the circuit is closed, as they will be hot Use a long wire to avoid having a large electric current flowing through it Open the circuit immediately after taking a reading and let the wires cool before touching them Take the reading on the multimeter Record your reading in the table on the next page Your teacher will repeat step 1 Take a second reading on the multimeter 62 Chapter 5 Record your reading in the table below Find the average of the two readings by adding them and dividing the total by two Record the average of the two readings in the table below Your teacher will repeat step 1 using an iron wire of the same length and thickness as the copper wire Repeat steps 2 to 7 Electric current in A Wire First reading Second reading Average reading first reading + second reading copper iron (Answer varies.) 10 Does the copper or iron wire allow a larger electric current to flow through the electric circuit? Which metal is a better electrical conductor? The copper wire allows a larger electric current to flow through the electric circuit than the iron wire Copper is a better electrical conductor than iron 11 Which variable is changed in this investigation? The type of wire / The material that the wire is made of 12 (a) Write down three variables that are kept the same The number of batteries / The type of battery / The thickness of the wire / The length of the wire / The arrangement of electrical components in the electric circuit (Any three) (b) Why are these variables kept the same? These variables are kept the same to ensure that the test is fair It lets us know that any difference in the electric current is caused by the type of material used to make the wire, and not by other factors More About Electricity 63 Worksheet Uses of Electrical Conductors and Insulators Aim: To observe and identify uses of electrical conductors and insulators in everyday objects Skills: Observing, identifying, communicating, analysing Some parts of a battery holder and hairdryer are made of electrical conductors, while other parts are made of electrical insulators I dentify the materials that make up the different parts of a battery holder and hairdryer Complete the tables provided (a) Battery holder contact case spring wire wire cover 64 Chapter Part of battery holder What material is it made of? Is the material an electrical conductor or insulator? Why is an electrical conductor or insulator used? case plastic electrical insulator prevent electric to current from flowing through the user to carry wire metal electrical conductor electric current to other electrical components in the electric circuit to prevent electric current in the wire cover plastic electrical insulator wire from flowing through the user to connect the negative end of the battery spring metal electrical conductor to the wire in the electric circuit, so that electric current can flow through the circuit positive to connect the end of the battery to the contact metal electrical conductor wire in the electric circuit, so that electric current can flow through the circuit More About Electricity 65 (b) Hairdryer motor wire coils switch button electric socket case plug cover wire cover wire 66 Chapter Part of hairdryer What material is it made of? Is the material an electrical conductor or insulator? Why is an electrical conductor or insulator used? case plastic electrical insulator prevent electric to current from flowing through the user to carry electric current wire metal electrical conductor from the electric socket to the motor wire coils and to prevent electric current in the wire cover plastic electrical insulator wire from flowing through the user to prevent switch button plastic electrical insulator electric current from flowing through the user to prevent plug cover plastic electrical insulator electric current from flowing through the user More About Electricity 67 Worksheet Circuit Diagrams Aims: • To analyse and draw circuit diagrams • To set up electric circuits based on circuit diagrams Skills: Observing, identifying, communicating, analysing What you need: Batteries, battery holders, bulbs, bulb holders, switches, wires Study this circuit diagram Will the bulbs in the electric circuit light up? Explain your answer No The batteries are connected wrongly as their negative ends are connected to each other Instead, the negative end of one battery should be connected to the positive end of the other battery 68 Chapter Use symbols to draw a circuit diagram for each electric circuit in the spaces (a) Circuit diagram More About Electricity 69 (b) Circuit diagram 70 Chapter Set up the electric circuits represented by these circuit diagrams Show the circuits to your teacher (a) (b) More About Electricity 71 Worksheet How Does Changing the Number of Electrical Components Affect an Electric Circuit? Aim: T o plan and carry out an investigation to find out how changing the number of batteries or bulbs connected in series affects the electric circuit Skills: Communicating, identifying variables, decision-making, observing, analysing, inferring, evaluating Work in groups Decide if you want to investigate whether the number of batteries or bulbs connected in series affects the electric circuit Discuss and write down a plan for your investigation You may follow these steps to help you plan your investigation: (a) Write down the aim of your investigation on the next page (b) Identify the variable to change (c) I dentify the variables to keep the same to ensure that the investigation is a fair test (d) W rite down the steps to be carried out This should include what you have to measure and observe, and in what form you will record your observations Draw diagrams to show the electric circuits you are going to set up in the investigation (e) Decide what materials you will need for the investigation Show your plan to your teacher Make changes to your plan if needed Carry out the plan Record your observations Write down the conclusion based on your observations 72 Chapter Our plan Aim (Answer varies.) Variable to change (Answer varies.) Variables to keep the same (Answer varies.) Materials (Answer varies.) Steps (Answer varies.) More About Electricity 73 (Answer varies.) Observations (Answer varies.) Conclusion (Answer varies.) 74 Chapter Evaluate how well you have planned and carried out your investigation by using this scoring guide or rubric Tick (✔) the appropriate boxes This will give you feedback on what you are good at and what you need to improve on when you plan and carry out an investigation Skill Very good Good Average Not very good Not good Identifying and communicating the aim of the investigation clearly Identifying the variables to change and keep the same Identifying and communicating the materials needed clearly Identifying and communicating the steps of the investigation clearly Identifying the observations to make Identifying the form of recording observations Making observations Recording observations Drawing a conclusion (Answer varies.) More About Electricity 75 Worksheet How Does Changing the Length of a Wire Affect an Electric Circuit? Aim: To find out how changing the length of a wire affects the amount of electric current flowing through an electric circuit Skills: Observing, communicating, analysing, inferring, identifying What you need: Multimeter, 1 m iron wire of about 1 mm in diameter, battery, battery holder, wire with crocodile clips Your teacher will use a multimeter to measure the amount of electric current flowing through an iron wire He or she will tap the black probe of the multimeter on point A, the midpoint of the iron wire battery black probe A multimeter iron wire B Do not touch the wires or any part of the electric circuit when the circuit is closed, as they will be hot Use a long wire to avoid having a large electric current flowing through it Open the circuit immediately after taking a reading and let the wires cool before touching them Take the reading on the multimeter Record your reading in the table on the next page Your teacher will repeat step 1 Take a second reading on the multimeter Record your reading in the table on the next page Find the average of the two readings by adding them and dividing the total by two 76 Chapter Record the average of the two readings in the table below Your teacher will repeat step 1 by tapping on point B, the end of the iron wire Repeat steps 2 to 7 Electric current in A Point on the iron wire First reading Second reading Average reading first reading + second reading A B (Answer varies.) 10 Does a shorter or longer wire allow a larger electric current to flow through the electric circuit? A shorter wire 11 Which variable is changed in this investigation? The length of the wire 12 Write down three variables that are kept the same to ensure that the test is fair The material that the wire is made of / The thickness of the wire / The number of batteries / The type of batteries / The arrangement of the electrical components in the electric circuit (Any three) 13 (a) Which variable should you change if you want to investigate whether the thickness of the wire affects the amount of electric current flowing through an electric circuit? The thickness of the wire (b) W rite down three variables that you should keep the same to ensure that the test is fair The material that the wire is made of / The length of the wire / The number of batteries / The type of batteries / The arrangement of the electrical components in the electric circuit (Any three) More About Electricity 77 Let s Review Fill in the blanks Electric current can easily flow through electrical such as insulators batteries bulbs such as graphite plastic • • rubber smaller the electric current which can be used to make copper • • gold • aluminium • t he thickness the wire — the that are electrical conductors which can be used to make • e lectrical and cables • lightning wires conductors covers • for electrical wires, plugs, sockets and switches • casings for electrical devices Chapter of thicker the wire, the larger the electric current in an electric circuit which can be represented by symbols in a circuit 78 and length • t he of the wire — the longer the wire, the such as good can be affected by • t he number of electrical components such as electrical conductors metals cannot easily flow through diagram Reflection Tick (✔) to show how well you have learnt Revise the Pupil s Book section(s) that you not know well I have learnt to Yes Not sure No Pupil s Book section(s) investigate the ways some materials are better electrical conductors than others A investigate the ways some metals are good electrical conductors and that most other materials are not A recognise why metals are used for cables and wires, and why plastics are used to cover wires, plugs and switches A represent series circuits with drawings and circuit symbols B predict and test the effects of changes to electric circuits, including the change in the number and type of electrical components, and the length or thickness of a wire C Suggestion(s) to Guide Pupils Worksheet 1: Demonstrate to pupils how to set up a circuit tester before they carry out the investigation Worksheet 2, 11 , 12 : Provide pupils with choices for the variables Worksheet 5: Guide pupils to plan the investigation first before letting them write their own plan Worksheet 6, 11 , 12 , 13 : Provide pupils with choices for the variables Let’s Review: Provide pupils with helping words More About Electricity 79 ... Tick (✔) to show how well you have learnt Revise the Pupil s Book section(s) that you not know well I have learnt to Yes Not sure No Pupil s Book section(s) investigate the ways some materials are... Provide pupils with choices for the variables Worksheet 5: Guide pupils to plan the investigation first before letting them write their own plan Worksheet 6, 11 , 12 , 13 : Provide pupils with choices... What you need: Multimeter, 1 m iron wire of about 1 mm in diameter, battery, battery holder, wire with crocodile clips Your teacher will use a multimeter to measure the amount of electric current