Lab 06 Electric Circuits (Inquiry Investigation)
Purpose
In this lab you will investigate how electric circuits work by building and testing circuits in the PhET Circuit Construction Kit simulation.
Instead of following a strict recipe, you will explore circuits, make predictions, test ideas, and develop rules that explain what you observe.
By the end of this lab you should be able to:
- Explain the conditions required for electric current to flow.
- Describe how voltage affects brightness.
- Distinguish between series circuits and parallel circuits.
- Use measurements of voltage and current to identify relationships in circuits.
- Draw clear circuit diagrams using standard symbols.
This lab is designed so that you discover relationships yourself through experimentation.
Simulation Link
Use this simulation for the entire lab:
- PhET: Circuit Construction Kit (DC)Links to an external site.
If the embedded simulation runs slowly, open it in a new tab.
Simulation (Embedded)
Setup
- Open the simulation.
- Select the Lab view if available.
- Locate the battery, wires, bulb, voltmeter, and ammeter.
- You may drag components anywhere and connect them freely.
What You Turn In
Submit ONE PDF. This should be a compact lab packet.
Your PDF must include these parts in this order:
- Part A exploration sketches (working and non-working circuits).
- Part A explanation questions.
- Part B materials table (conductors vs insulators).
- Part C voltage investigation table.
- Part D series circuit diagram and answers.
- Part E parallel circuit diagram and answers.
- Part F Ohm’s Law data table and graph.
- Part G circuit design challenge diagram and explanation.
- Final reflection questions.
Important expectations:
- Circuit diagrams must be hand drawn.
- Diagrams must use standard circuit symbols.
- Graphs must be made in Excel or Google Sheets.
- Axes must be labeled with variables and units.
- Submit everything as one PDF.
Part A — Lighting a Bulb
Goal: Determine how to light a bulb using the fewest components.
Use only:
- battery
- wire
- bulb
Procedure
- Experiment freely with the components.
- Find two different arrangements that light the bulb.
- Find two arrangements that do NOT light the bulb.
Your PDF must include:
- Four sketches of your circuits.
- A short explanation of what conditions are required for a bulb to light.
Part B — Conductors and Insulators
Place different objects in the circuit path and test whether current flows.
Test at least five materials.
Create a table like this:
| Material | Bulb Lights? | Conductor or Insulator |
|---|
Answer:
- What types of materials allow current to flow?
- Why might metals behave differently than rubber or plastic?
Part C — Voltage and Brightness
Build a circuit with:
- one bulb
- one battery
Then add additional batteries.
Record your observations.
| # Batteries | Voltage (V) | Brightness |
|---|
Questions:
- How does voltage affect brightness?
- What do you think voltage represents physically?
Part D — Series Circuits
Build a circuit with two bulbs in series.
Procedure
- Observe brightness.
- Remove one bulb.
Your PDF must include:
- A clear series circuit diagram.
- A short explanation of what happens when one bulb is removed.
Part E — Parallel Circuits
Build a circuit with two bulbs in parallel.
Procedure
- Observe brightness.
- Remove one bulb.
Your PDF must include:
- A clear parallel circuit diagram.
- An explanation of how this behavior differs from the series circuit.
Part F — Investigating Ohm’s Law
Build a circuit containing:
- battery
- resistor
- voltmeter
- ammeter
Change the battery voltage and record measurements.
| Voltage (V) | Current (A) |
|---|
Graph:
- Plot Current vs Voltage.
- Create a scatterplot.
- Add a best-fit line.
- Display the equation and R².
Answer:
- Is the relationship linear?
- What law might explain this relationship?
Part G — Circuit Design Challenge
Design a circuit with three bulbs such that:
- One bulb can be removed
- The other bulbs remain on
Your PDF must include:
- A sketch or screenshot of your circuit.
- A clean circuit diagram.
- A short explanation of how it works.
Optional Extra Credit — Real Circuit Build
You may earn up to 5 additional points by building a real circuit.
Possible materials:
- AA batteries
- copper wire
- flashlight bulb
- paper clips
- aluminum foil
Submit:
- A photo of your working circuit
- A circuit diagram
- A short explanation of what worked and what challenges you encountered
Final Reflection Questions
- What patterns did you observe about current and voltage in circuits?
- What is the key difference between series and parallel circuits?
- What advantages do simulations provide for learning circuits?
- What limitations do simulations have compared with building real circuits?
Formatting Rules
- Submit one PDF.
- All circuit diagrams must be clear and readable.
- Graphs must include units and labels.
- Explanations should be complete sentences.
How to Turn It In
- Please submit a single document that includes the following sections: Introduction, Methods, Results, and Conclusion. All procedures performed and questions answered in this lab should be clearly incorporated into one of these sections.