Circuits & IV Graphs

Overview

This 60-minute lesson is designed for Set 3 GCSE students following AQA specifications and aligns closely with the National Curriculum for England Science programme of study (Key Stage 4 - Physics). It focusses on understanding and interpreting current-voltage (IV) characteristics graphs and the differences between series and parallel electrical circuits.

Curriculum Links

Topic: Electricity
KS4 Physics Programme of Study (NC, England)
P2.1, P2.2 - Electrical circuits, components and characteristics
Students should be able to:
- Understand how current varies with potential difference for different circuit elements.
- Draw and interpret IV graphs for resistors, diodes, and filament lamps.
- Understand differences between series and parallel circuits including current, voltage, and resistance behaviour.
AQA GCSE Physics Specification
- Physics Paper 1 - Electricity
- Required practical: IV characteristics of a component

Learning Objectives (WALT)

WALT interpret IV graphs from experimental data and explain behaviour of components.
WALT compare and explain current and potential difference across components in series and parallel circuits.

Success Criteria

By the end of this lesson, students will be able to:

Plot and interpret IV graphs from given data (including recognising linear and nonlinear relationships).
Describe how current and voltage behaves in series and parallel circuits.
Explain, using the IV graph, the behaviour of resistors and filament lamps in circuits.
Construct and analyse simple series and parallel circuits using circuit symbols.

Resources

Circuit components: resistors, filament lamps, batteries, ammeters, voltmeters
Power supplies (low voltage)
A3 IV graph worksheets (differentiated)
Series and parallel circuits worksheets (differentiated)
Coloured pens/pencils for graph work
Whiteboard & markers
Dyslexia-friendly fonts printed handouts with key definitions and diagrams (use sans-serif, coloured backgrounds)

Lesson Structure

1. Starter (10 minutes)

Activity: Think-Pair-Share on circuit basics

Students recall prior knowledge: What is current? What is voltage?
Teacher asks: “What do you think an IV graph tells us about a component?”
Share examples verbally and write simple definitions on board.
Show very simple IV graph and highlight axes (current on y, voltage on x).

Differentiation: Provide sentence starters for verbal answers; pair weaker learners with peers for support.

2. Main Activity Part 1: IV Graphs (20 minutes)

Teacher Explanation (5 mins):
- Introduce actual IV graph for a resistor (linear), filament lamp (nonlinear), diode (nonlinear with threshold).
- Relate graph shape to physical behaviour of component.
Worksheet Task (15 mins):
- Students receive a data table of voltage and current for a filament lamp and resistor.
- Using A3 graph paper and coloured pencils, plot the IV graphs.
- Answer questions: Describe differences between graphs, explain why behaviours differ.

Differentiation:

Provide simplified data sets for weaker learners with pre-printed graph grids.
Extension: Challenge advanced learners to sketch IV graph for diode from a data description or explain practical applications.

Dyslexia-friendly option: Worksheets in clear font, with ample spacing, and colour-coded axes.

3. Main Activity Part 2: Series & Parallel Circuits (20 minutes)

Teacher Explanation (5 mins):
- Recap circuit symbols and differences between series and parallel circuits.
- Explain current and voltage behaviour in both types.
- Show schematic diagrams and highlight respective behaviours.
Practical/Worksheet (15 mins):
- Using circuit diagrams (or actual components, time permitting), students complete worksheet comparing series and parallel circuits.
- Label current and voltage values on diagrams.
- Question: “Predict total resistance in each circuit and explain reasoning.”

Differentiation:

Provide labelled diagrams for struggling learners; focus questions on identifying current flow and voltage splits.
Extension activity for advanced students: Calculate total resistance and total current using Ohm’s law for different configurations.

4. Plenary (10 minutes)

Students complete an exit ticket:
1. What does an IV graph show?
2. How does current behave in a series circuit?
3. How does voltage behave in a parallel circuit?
Class discussion of answers, correcting misconceptions.
Teacher highlights real-life applications: why understanding IV graphs and circuit types matter (e.g., in electronics and household wiring).

Assessment

Formative assessment through worksheet answers and exit tickets.
Teacher monitors during graph plotting and circuit questions.
Targeted questioning to check concept grasp during plenary.

Differentiation Summary

Learner Need	Strategies/Support
Struggling with graph skills	Colour-coded axes, pre-drawn axes, paired work
Dyslexia	Dyslexia-friendly fonts, simplified language, printed glossary
More able	Extension activities calculating resistance/current, explaining diode IV behaviour
EAL learners	Visual aids, clear definitions, paired talk before writing

Extension Ideas

Investigate IV graphs for non-ohmic conductors such as LEDs and thermistors.
Design a simple circuit incorporating both series and parallel components; draw and explain IV graphs for each.
Research household wiring and explain why parallel circuits are used instead of series.

Teacher Notes

Prepare equipment in advance for practical demonstration if possible.
Emphasise correct labelling on graphs and circuit diagrams as this is a key GCSE skill.
Use questioning to challenge misconceptions, e.g. “If you increase voltage, what happens to current in a filament lamp?”
Encourage use of physics keywords: voltage, current, resistance, series, parallel, linear, nonlinear.

This plan ensures students master core GCSE Electricity skills: interpreting IV characteristics and understanding circuit configurations, providing differentiated paths for diverse learners and a dyslexia-friendly approach to maximise accessibility.

Teaching Instructions