Electrical Conductors and Insulators (Primary Science)

Imagine you have a toy robot and a stack of batteries ready to bring it to life. But how can you determine if the batteries still have the power to make the robot move? This is where the fascinating world of electrical conductors and insulators, essential concepts in Primary Science and PSLE curriculum, comes into play.

In this educational article, specifically designed for Primary Science and PSLE students, we will embark on an electrifying journey to understand the concepts of electrical conductivity. We’ll explore how certain materials can conduct electricity, while others act as barriers, preventing the flow of electric current.

Important Terms to Know

• Electrical Conductors: Materials that allow electricity to pass through (metals, water, carbon). They are good conductors of electricity.
• Electrical Insulators: Materials that do not allow electricity to pass through (glass, rubber, wood, plastic). They are poor conductors of electricity.
• Open Circuit: Like a broken path for electricity. In this state, electricity cannot travel through the circuit.
• Closed Circuit: A closed circuit is the opposite; it’s a complete loop that allows electricity to flow freely. In this state, electricity travels through the circuit.

Primary Science Question on Electrical Conductors and Insulators: Ai Tong Primary School 2019 Prelim Q39

Let’s start by introducing a helpful tool known as a circuit tester. By using this device, we can investigate whether the batteries in our toy robot still have the power to make it spring into action. Get ready to dive into the exciting realm of electrical conductors and insulators as we unravel the secrets behind electrical circuits and discover the materials that make them work.

So, young scientists, grab your curiosity and join us on this electrifying adventure to expand your knowledge of electrical conductors and insulators. Let’s unlock the mysteries of electricity and delve into the captivating world of circuits!

Let’s explore how a circuit tester works using this Primary Science (Electricity) question:

Justin set up a circuit as shown below to find out which objects A, B, C or D are electrical conductor(s).

PART A:

(a) What is the purpose of the light bulb in the circuit? (1 mark)

Key information: The diagram shows a circuit tester, used to test whether objects A, B, C and D are conductors.

EXAMPLE:

So, how does a circuit tester work? Let’s explain using a simpler circuit.

Linking back to the question:

So, just like in our earlier example, the bulb in this circuit helps us to determine whether electricity is running through the circuit and materials A, B, C or D by lighting up.

Suggested Answer

a) By lighting up or not lighting up, the bulb acts as an indicator to tell us whether the material is an electrical conductor.

PART B:

Justin recorded his observations in the table below.

(b) Justin’s teacher commented that test 1 is not useful as it would not help him find out if any of the objects are electrical conductors. Explain why that teacher said so. (2 marks)

Let’s draw the circuit according to test 1. With switch X closed, and switch Y and Z open, the circuit will look like this:

Possible pathways for electricity to flow:

Suggested answer:

(b) With only switch X closed, the circuit will be open, and electricity cannot flow through the circuit. Therefore, the bulb will not light up and be able to indicate whether the object is an electrical conductor.

PART C:

(c) From the results of Justin’s experiment, which of the objects A, B, C and/or D are definitely electrical conductor(s)?  

First, let’s look at his results for each test.

Summarising the results of all tests, we know that objects B, C, and D are definitely conductors.

Suggested answer:

• Objects B, C and D.

Conclusion:

A circuit tester is like a special tool that helps you check if something can conduct electricity. For example, to check whether your batteries are still working.

In the question, Justin wants to find out whether the objects conduct electricity. Why do you think we want to know whether a material is an electrical conductor?

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