1 What is? a. There are four items in Tom s room that use electricity to work. Circle these items in the picture below. b. Name four other items around you that use electricity to work. 1. 2. 3. 4. c. Name four items around you that do not use electricity to work. 1. 2. 3. 4. 2012 Alston Publishing House Pte Ltd Science SMART Teacher s Guide Grade 5 275
2 What is an Circuit? a. A simple circuit can be made up of the four basic components shown in the table below. State the function of each component and draw its symbol. Component Function Symbol Switch Battery Wire Bulb 276 Additional Teacher s Resources 2012 Alston Publishing House Pte Ltd
b. Draw the circuit diagrams to represent each of the following electric circuits. Electric circuit Circuit diagram 2012 Alston Publishing House Pte Ltd Science SMART Teacher s Guide Grade 5 277
c. You are provided with a switch, two lightbulbs, two batteries and some connecting wires. i. Draw a circuit diagram to show that all the components in the circuit are arranged in series. ii. Draw a circuit diagram to show that only the lightbulbs are arranged in parallel. d. Study the circuit below. S1 B1 S2 B2 Will the lightbulbs up when the following combinations of open/closed switches are used? Write your answers Yes or No in the boxes in the table below. S1 S2 B1 B2 Open Closed Closed Open 278 Additional Teacher s Resources 2012 Alston Publishing House Pte Ltd
3 What Happens When Parts of a Circuit Are Changed? Look at the group of circuits below. In which circuit will the lightbulb shine the brightest when the switch is closed? a. The brightest lightbulb is in Circuit. A B C b. The brightest lightbulb is in Circuit. D E F c. The brightest lightbulb is in Circuit. G H I d. The brightest lightbulb is in Circuit. W X Y Z 2012 Alston Publishing House Pte Ltd Science SMART Teacher s Guide Grade 5 279
4 What Are Conductors and Insulators of? / How Can We Use Safely? a. The items shown below are either electrical conductors or insulators. Circle only the electrical conductors. Plastic spoon Ceramic cup Gold chain Wooden chopsticks Metal fork Cloth Copper coin Rubber hose Safety pins Aluminium foil Cardboard Silver vase 280 Additional Teacher s Resources 2012 Alston Publishing House Pte Ltd
b. Why must we handle electricity safely? c. Which of the following actions below should you do or not do when handling electricity? Write Do or Do not in the boxes provided. Touching an electrical device or socket with wet hands. Have a repair man fix socket when it is broken. Have many plugs connected to one socket. Keep electrical appliances in a dry area, away from water. Turn off a switch before removing a plug from a socket. 2012 Alston Publishing House Pte Ltd Science SMART Teacher s Guide Grade 5 281
Fun and Games Electron Around the Circuit Electron needs to move from Point A to Point B in the direction shown below. Point A Point B START END Glass Copper Wooden Iron Steel There are several paths from Point A to Point B. However, Electron can only travel through s that are conductors of electricity. Help Electron reach Point B by tracing the path he can take. 282 Additional Teacher s Resources 2012 Alston Publishing House Pte Ltd
Exam Practice Process skills: Observing, Analysing, Communicating The picture below shows a circuit diagram. Study the diagram carefully and answer the questions that follow. P Lightbulb A Lightbulb B a. If Object P is a conductor, which of the lightbulbs would light up? [1 mark] b. If Object P is an insulator, which of the lightbulbs would light up? [1 mark] c. Where would you break the circuit to make sure that neither of the lightbulbs will light up? Mark your answer on the circuit with an X. [1 mark] Hint: How can you make open circuits for both the bulbs using only one break? 2012 Alston Publishing House Pte Ltd Science SMART Teacher s Guide Grade 5 283
Chapter 4 Answers to Additional Teacher s Resources Answers to Additional Teacher s Resources 1 2 What is? What is an Circuit? a. There are four items in Tom s room that use electricity to work. Circle these items in the picture below. a. A simple circuit can be made up of the four basic components shown in the table below. State the function of each component and draw its symbol. Component Function Symbol Used to open and close the circuit Switch Provides energy to the components in the circuit Battery b. Name four other items around you that use electricity to work. Used to connect the different components together 1. 2. 3. 4. (Accept all possible answers.) c. Name four items around you that do not use electricity to work. Wire Helps detect current flowing through the circuit by lighting up 1. 2. 3. 4. (Accept all possible answers.) Bulb 284 Additional Teacher s Resources 2012 Alston Publishing House Pte Ltd
b. Draw the circuit diagrams to represent each of the following electric circuits. c. You are provided with a switch, two lightbulbs, two batteries and some connecting wires. Electric circuit Circuit diagram i. Draw a circuit diagram to show that all the components in the circuit are arranged in series. (Accept all possible answers.) ii. Draw a circuit diagram to show that only the lightbulbs are arranged in parallel. (Accept all possible answers.) d. Study the circuit below. S1 B1 B2 S2 Will the lightbulbs up when the following combinations of open/closed switches are used? Write your answers Yes or No in the boxes in the table below. S1 S2 B1 B2 Open Closed Yes Yes Closed Open Yes No Answers to Additional Teacher s Resources Answers to Additional Teacher s Resources 2012 Alston Publishing House Pte Ltd Science SMART Teacher s Guide Grade 5 285
4 What Are Conductors and Insulators of? / How Can We Use Safely? a. The items shown below are either electrical conductors or insulators. Circle only the electrical conductors. Plastic spoon Ceramic cup Gold chain Wooden chopsticks Metal fork Cloth Copper coin Rubber hose Safety pins Aluminium foil Cardboard Silver vase 3 What Happens When Parts of a Circuit Are Changed? Look at the group of circuits below. In which circuit will the lightbulb shine the brightest when the switch is closed? a. The brightest lightbulb is in Circuit C. A B C b. The brightest lightbulb is in Circuit D. D E F c. The brightest lightbulb is in Circuit H. G H I d. The brightest lightbulb is in Circuit X. W X Y Z 286 Additional Teacher s Resources 2012 Alston Publishing House Pte Ltd
b. Why must we handle electricity safely? If we do not handle electricity safely, we can get seriously injured and can cause harm to our surroundings, such as starting fires. Fun and Games Electron Around the Circuit c. Which of the following actions below should you do or not do when handling electricity? Write Do or Do not in the boxes provided. Electron needs to move from Point A to Point B in the direction shown below. Do not Touching an electrical device or socket with wet hands. Point A Point B Do Have a repair man fix socket when it is broken. START END Do not Have many plugs connected to one socket. Glass Do Do Keep electrical appliances in a dry area, away from water. Turn off a switch before removing a plug from a socket. Wooden Copper Iron Steel There are several paths from Point A to Point B. However, Electron can only travel through s that are conductors of electricity. Help Electron reach Point B by tracing the path he can take. Answers to Additional Teacher s Resources Answers to Additional Teacher s Resources 2012 Alston Publishing House Pte Ltd Science SMART Teacher s Guide Grade 5 287
Hint: Chapter 4 Answers to Additional Teacher s Resources Exam Practice Process skills: Observing, Analysing, Communicating The picture below shows a circuit diagram. Study the diagram carefully and answer the questions that follow. Lightbulb A P Lightbulb B X X X a. If Object P is a conductor, which of the lightbulbs would light up? [1 mark] Lightbulbs A and B. b. If Object P is an insulator, which of the lightbulbs would light up? [1 mark] Lightbulb B. c. Where would you break the circuit to make sure that neither of the lightbulbs will light up? Mark your answer on the circuit with an X. [1 mark] (Mark an X on either side of the battery or Lightbulb B.) How can you make open circuits for both the bulbs using only one break? 288 Additional Teacher s Resources 2012 Alston Publishing House Pte Ltd
Glossary Chapter 4: Circuit diagram Closed circuit Component Conductor Electric circuit Electric current Insulator Open circuit Parallel circuit Series circuit Symbol A drawing that uses symbols to represent an actual electric circuit A circuit that has a complete path for electricity to flow A part of something A material that electricity flows through easily A form of energy A path in an electrical device that allows electric current to flow The flow of particles carrying electrical energy around a circuit A material that does not allow electricity to flow through easily A circuit that does not have a complete path for electricity to flow A circuit that has more than one path for electricity to flow A circuit that has only one path for electricity to flow Something that is used to represent the parts or components that make up a circuit 2012 Alston Publishing House Pte Ltd Science SMART Teacher s Guide Grade 5 289