Year 9 Science · Unit 3 · Lesson 17

Circuit Symbols, Voltage, Current and Resistance

Challenge Worksheet

Name
Date
Class

Learning Goals

Warm Up

Because… chain

Fill in the missing effects to complete the electron flow story in a simple circuit. Each cause leads directly to the next effect.

Electrons have a negative charge
→
The cell creates a potential difference (voltage)
→
Electrons are repelled from the negative terminal
→
Electrons flow through the filament of the bulb
→
Electrons return to the positive terminal of the cell
→

Overall outcome:

Go Deeper

Design a mini-experiment

A scientist wants to test: "Does the length of a wire affect its resistance in a simple circuit?" Plan the investigation below using the boxes provided.

Aim
What I will change (independent variable)
What I will measure (dependent variable)
What I will keep the same (controlled variables, list at least 3)
Materials needed
Method steps (brief numbered list)
Safety consideration
Predicted result (with reasoning)
How would I display the data? (type of graph and axes)
One limitation of this experiment

Show What You Know

1. Conventional current flows from positive to negative, but electrons actually flow from negative to positive. Explain why this does not cause a problem in practice when we analyse circuits.

Challenge 2 marks

2. A student claims: "Adding more batteries to a circuit always makes the bulb brighter." Evaluate this claim, under what conditions is it true, and when might it be false or dangerous?

Challenge 3 marks

Wrap Up

In one sentence, what was the main idea of this lesson?

HSCScience · Year 9 Science · Unit 3 · Lesson 17 · Challenge Worksheet