Lesson 3: From Materials to Systems – Building and Understanding Simple Circuits

• How do we control the flow of electricity?
• What is required to complete a circuit?
• What happens when a circuit is open versus closed?
• How does material choice influence system reliability?
• How does a simple circuit model prepare us to understand complex boards?

Circuit
Closed circuit
Open circuit
Load
Power source
Switch
Current
Pathway
Connection
Short circuit
Series
Parallel

HS PS2-6
Communicate scientific information about how molecular structure influences the functioning of designed materials.

Science and Engineering Practices:

Planning and Carrying Out Investigations
Developing and Using Models
Constructing Explanations

Crosscutting Concepts:

Systems and System Models
Cause and Effect
Structure and Function

• Interpreting diagrams
• Following procedural instructions
• Identifying cause-and-effect relationships
• Writing structured explanations
• Comparing models

Students practice translating between physical systems and symbolic diagrams.

Day 1 – Building a Basic Circuit

Students receive:

Battery pack
Wires
Light bulb or LED
Optional switch

Students are tasked with lighting the bulb.

They must determine:

What completes the circuit
Why both leads must connect
What happens when the path is broken

Students draw a simple circuit diagram representing their setup.

Purpose:
Move from material properties to system organization.

DOK: 2 – Construct and observe system behavior.

Day 2 – Modifying and Testing Circuits

Students experiment with:

Adding a switch
Reversing polarity
Introducing an insulator
Creating a short circuit

They answer:

Why does a short circuit bypass the load?
Why does insulation prevent current flow?
How does series versus parallel change behavior?

Students update their diagrams.

Purpose:
Deepen understanding of controlled electrical flow.

DOK: 3 – Analyze cause-and-effect changes within system.

Day 3 – Connecting Structure to System

Students revisit molecular reasoning:

Why must wires be conductive?
Why is insulation necessary?
Why do we not use graphite rods for all wiring?

Students write a structured explanation connecting:

Material structure ? Conductivity ? Circuit function ? System reliability

Purpose:
Integrate Segments 1 and 2 with system design.

DOK: 3 – Construct multi-step explanation.

Optional Day 4 – Predictive Troubleshooting

Students are given circuit diagrams with faults.

They predict:

Will the bulb light?
Where is the failure?
Why?

Students justify predictions using system reasoning.

Purpose:
Prepare for analyzing complex circuit boards in next segment.

DOK: 3

Students connect simple circuits to:

Light switches at home
Phone chargers
Car wiring systems
Holiday light strings

They recognize that all complex digital devices begin with simple circuit logic.

• Electricity is “used up” as it flows.
• One wire is sufficient to complete a circuit.
• Insulation blocks electricity because it is thick rather than non-conductive.
• Switches create electricity rather than control flow.
• Short circuits are harmless.

Teacher pushes students to describe current as a continuous loop, not a one-directional line.

• Provide circuit templates for students who need visual structure.
• Offer step-by-step assembly checklists.
• Allow collaborative troubleshooting.
• Provide guided questions for diagram explanation.
• Extension: Introduce parallel circuit challenge for advanced students.

Formative Assessments:

• Functional circuit construction
• Labeled circuit diagram
• Written explanation connecting material choice to function

Exit Ticket Prompt:

Explain why a circuit requires a complete conductive loop.
Use both system and material reasoning in your explanation.

Evaluation Criteria:

Accuracy of circuit construction
Correct diagram representation
Clear cause-and-effect explanation
Integration of material structure and system function