Circuit Pathways

Overview

In this lesson (Lesson 4 of 9) students distinguish between series and parallel circuits by building and comparing simple circuit arrangements. They focus on how the energy transfers through components and how the circuit design changes what happens to bulbs.

Learning intentions

WALT distinguish between series and parallel circuits and describe how each affects energy flow and bulb brightness.

Success criteria

• I can explain how many pathways electricity has in a series circuit compared with a parallel circuit.
• I can compare what happens to all bulbs when one component is changed in each circuit type.
• I can use circuit diagrams (including arrows for electricity flow) to represent series and parallel circuits accurately.
• I can discuss my findings using evidence from my own or my group’s observations.

Curriculum links

• AC9S6U03: investigate transfer and transformation of energy in electrical circuits, including the role of circuit components, insulators and conductors.
• AC9S6I01: pose investigable questions, identify patterns, test relationships, and make reasoned predictions about circuit function.
• AC9S6I04: construct and use appropriate representations to organise and process data and describe patterns (tables/diagrams for circuit comparisons).
• AC9S6I02: plan and conduct repeatable investigations with variables and safe equipment use when building circuits.
• AC9S6I05: compare methods/findings with others, recognise sources of error, and draw reasoned conclusions based on evidence.

Lesson structure (45 minutes)

1. 0–5 min · Hook (quick demonstration). Teacher shows two pre-made circuits (series and parallel) with identical bulbs and briefly switches one bulb off/removed in each. Students predict: “In which circuit will the other bulb(s) change, and why?”

2. 5–12 min · Direct teach (series vs parallel). Teacher uses a labelled diagram to explain: series = one continuous pathway; parallel = multiple pathways. Teacher highlights that electrical energy is transferred by the power source, and components affect how current travels through conductors, with air/insulation preventing flow. Students annotate a simple comparison sheet with two key features (pathways and bulb behaviour).

3. 12–30 min · Build and investigate (group stations, repeatable).

• Teacher allocates roles (builder, switch-controller, recorder, safety-checker).
• Group builds one series circuit and one parallel circuit using the same items (same power source, same number of bulbs, same wires). Students complete two trials:
• Trial A: Light both bulbs in each circuit, observe brightness (or on/off behaviour).
• Trial B: Change one bulb (remove one bulb or open the switch affecting one branch) and observe what happens to the other bulb(s). Teacher reminds: only change one thing at a time and keep other parts the same. Students record observations in a table: “Circuit type / Change / What happened to bulb 1 / What happened to bulb 2.”

4. 30–38 min · Data to discussion (class comparison). Teacher facilitates a structured group discussion using sentence starters: “We noticed that…”, “Our evidence shows…”, “A reason this happens is…”. Students compare their series vs parallel findings and adjust any incorrect predictions.

5. 38–44 min · Represent and justify (mini diagram task). Teacher provides a blank diagram template with a power source, two bulb positions, and wire paths. Students draw one series and one parallel circuit, adding arrows to show direction of electricity flow and labelling where the pathway(s) are.

6. 44–45 min · Exit ticket (quick check). Students answer: “If one bulb fails, which circuit type keeps the other bulb working more reliably, and why?” Teacher collects immediately.

Resources

• Circuit kits (power source, wires/leads, two bulbs, bulb holders, switches)
• Diagrams template for series and parallel
• Observation recording sheet with a simple table
• Bulb removal tool or safe method for opening one part of the circuit
• Safety reminders card (no skin contact with exposed metal, handle bulbs carefully)
• Rulers/measuring tape only if needed for consistent wire length
• Whiteboard/markers and a class example circuit diagram

Assessment

• Formative: teacher circulates during builds, checking correct identification of series/parallel features and safe practices.
• Formative: observation table accuracy (students record changes consistently and relate to circuit type).
• Exit ticket: identifies whether students can explain differences using evidence.

Differentiation

• Support: provide partially completed diagrams and a word bank (“pathway”, “series”, “parallel”, “one route”, “two routes”, “switch”, “bulbs”) plus sentence starters for discussion.
• Support: use picture icons on the recording sheet (bulb on/off) so students can record observations even if writing is difficult.
• Extension: challenge students to predict brightness differences if bulbs are replaced with different bulb types (e.g., one dimmer bulb) while keeping the circuit type the same.
• SEN/EAL: assign clear roles (builder/recorder/safety-checker) and allow oral responses for the exit ticket if needed; confirm meaning of “pathway” using concrete examples with wire routes.

Success criteria check (for each lesson phase)

• After Hook: students make a reasoned first prediction about bulb behaviour.
• During Build: students keep variables controlled (only one change in Trial B).
• After Discussion: students can state a comparison claim about circuit pathways and observed outcomes.
• After Exit Ticket: students justify their choice of circuit type using evidence from observations.