Quick answer: A simple electric circuit is a complete, closed loop of conductors that joins a cell to components such as a bulb and a switch. This grade 6 science lab on simple circuits gives the aim, the equipment, the safety points, a step-by-step method, sample results and 7 analysis questions; the answers are on a separate page and the lab sheet is a free printable PDF.
Which everyday objects let electric current flow? In this lab you build a tester circuit with a cell and a bulb and place each object in a gap. The brightness of the bulb lets you sort conductors from insulators, and a painted key shows why surface coatings matter.
Level: Grade 6 science (Year 7 · Class 6) · Curriculum: MS-PS2-3
Aim
To find which everyday objects conduct electricity, using a simple tester circuit.
Equipment
- One 1.5 V cell in a holder
- One 1.5 V bulb in a holder
- Four connecting wires with crocodile clips
- Ten objects: iron nail, copper wire, aluminium foil, pencil lead, plastic ruler, rubber eraser, glass slide, wooden stick, coin, painted steel key
Safety
Use only the cell supplied. Never connect any part of the circuit to a mains socket. Do not leave the circuit connected for long, because wires and the cell can become warm.
Method
- Build the tester circuit shown, leaving a gap between two clips.
- Check that the bulb lights when the two clips touch each other.
- Attach the clips to the first object and record whether the bulb is bright, dim or off.
- Repeat for the other objects. For the painted key, test the painted handle and then a scraped or unpainted part.
- Classify each object as a conductor or an insulator.
Results
Sample measurements:
| Object | Material | Bulb |
|---|---|---|
| Iron nail | Iron | Bright |
| Copper wire | Copper | Bright |
| Aluminium foil | Aluminium | Bright |
| Pencil lead | Graphite | Dim |
| Plastic ruler | Plastic | Off |
| Rubber eraser | Rubber | Off |
| Glass slide | Glass | Off |
| Wooden stick | Wood | Off |
| Coin | Metal alloy | Bright |
| Painted key: handle | Paint | Off |
| Painted key: bare blade | Steel | Bright |
Analysis questions
Question 1 Classification
Use the results to make a list of conductors and a list of insulators.Question 2 Pattern
State a pattern for the materials that conduct and the materials that do not.Question 3 The painted key
Explain why the key gave two different results.Question 4 Dim bulb
Suggest why the bulb was dim with the pencil lead.Question 5 Fair test
State two things that should be kept the same for every object.Question 6 Safety
Explain why the tester must never be made with mains electricity.Question 7 Improvement
Suggest how to make the results more precise.
