You will learn
- Define open and closed circuit.
- Predict lamp behaviour.
- Find breaks.
- Explain current flow in a loop.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Closed circuits have current.
- Open circuits have none.
- A break may be a gap, loose wire or blown lamp.
- Current flows around the loop.
Words to know
a complete loop where current flows
a loop with a gap, so no current
the flow of electricity
a gap in a circuit
1. Discover: The mystery circuit
Group G is given a circuit with a lamp that will not light. They trace the loop with a finger. At one corner, a wire has come loose. They press it back and the lamp lights. “The circuit was open,” says Yaa. “Now it is closed.”
Think: How did they find the break?
2. Understand: Open or closed
Idea 1: Closed circuit
In a closed circuit every part is connected in an unbroken loop. Current, the flow of electricity, goes around and the lamp lights.
Idea 2: Open circuit
In an open circuit there is a break: a gap, a loose wire, an open switch or a blown lamp. The current cannot flow and the lamp is off.
Idea 3: Tracing faults
Trace the loop with a finger from the cell, through every component, back to the cell. The place where the loop is broken is the fault.
3. Worked examples
Example 1 (I show you): Predict
Complete loop.
- Closed.
- Current flows.
- Lamp on.
Answer: The lamp lights.
Example 2 (We do it together): Predict
Wire disconnected.
- Open.
- No flow.
- Lamp off.
Answer: The lamp stays off.
Example 3 (You try): Find
Trace the loop.
Show the steps and answer
- Finger on wire.
- Find the gap.
- Fix.
Answer: Trace with your finger.
Did you know?
Electricians trace faults the same way: by following the circuit until they find the break.
Why this matters
Understanding circuits helps us fix problems and stay safe.
4. Explore: Break finder
Find breaks in four circuits and fix them.
- Trace each circuit.
- Find the break.
- Fix it.
- Record what you found.
Think about it: what did you notice?
What did you notice? Breaks were often at loose connections.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- A ___ circuit has a complete loop.
- An ___ circuit has a gap.
- ___ is the flow of electricity.
- A ___ is a gap in a circuit.
Guided practice
Question 1. What is a closed circuit?
Complete loop.
Question 2. What is open?
Gap.
Question 3. What is current?
Flow.
Independent practice
Level 1: Start
- What is a closed circuit?
- What is open?
- What is current?
- Does an open circuit light?
- How find a break?
Level 2: Grow
- Why trace?
- Why disconnect before fixing?
- Why a loop?
Level 3: Stretch
- Predict lamps.
- Find breaks.
- Draw closed and open.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Explain why a lamp stays off.
Show a sample answer
Use open and closed.
Another one. Tell a family member one thing from this lesson. Use the words you learned.
Show a sample answer
A clear sentence that uses at least one word from Words to know.
7. Common mistakes
Fix: It flows around.
Fix: It is a break.
8. Lesson summary and revision card
- I can define open and closed circuit.
- I can predict lamp behaviour.
- I can find breaks.
- I can explain current flow in a loop.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- Closed circuits have current.
- Open circuits have none.
- A break may be a gap, loose wire or blown lamp.
- Current flows around the loop.
11. Next lesson
Next lesson: Conductors and insulators. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- Define open and closed circuit. [2 marks]
- Predict whether three circuits light and explain. [3 marks]
- Describe how to find a break. [3 marks]
- Safety rules. [2 marks]
Total: 10 marks.
Marking guide and model answers
- Open [1]; closed [1]
- 1 each
- Trace [1]; find gap [1]; fix [1]
- 1 each
Score guide: 9 to 10 = secure. 6 to 8 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- What is a closed circuit?
- What is open?
- What is current?
- Does an open circuit light?
- How find a break?
- Why trace?
- Why disconnect before fixing?
- Why a loop?
- Predict lamps.
- Find breaks.
Homework
Draw one open and one closed circuit and explain which lights.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What is a closed circuit? | Complete loop. | 1 |
| 2. What is open? | Gap. | 1 |
| 3. What is current? | Flow. | 1 |
| 4. Does an open circuit light? | No. | 1 |
| 5. How find a break? | Trace the loop. | 1 |
| 6. Why trace? | Find the fault. | 1 |
| 7. Why disconnect before fixing? | Safety. | 1 |
| 8. Why a loop? | Current returns. | 1 |
| 9. Predict lamps. | Table. | 1 |
| 10. Find breaks. | List. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Complete loop.; 2 Gap.; 3 Flow.; 4 No.; 5 Trace the loop.. Level 2: 1 Find the fault.; 2 Safety.; 3 Current returns.. Level 3: 1 Table.; 2 List.; 3 Diagram..
Quiz answers: 1 B, 2 C, 3 A, 4 B, 5 C, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 B, Challenge 2 C.
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Define open and closed circuit | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Predict lamp behaviour | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Find breaks | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Explain current flow in a loop | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: “Current is used up by the lamp.” It flows around.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Explain open and closed circuits.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child finds breaks in circuits. You do not need to be an expert to help.
- Trace a torch circuit.
- Ask “Where is the loop?”
- Use batteries only.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: define open and closed circuit; predict lamp behaviour; find breaks; explain current flow in a loop.
Prerequisite knowledge. Grade 3 physical ideas: forces, magnets, materials and measuring in fair tests.
Materials. Cells, lamps, wires. Low-resource options: use chalk or charcoal on a board or wall, drawings in the sand, and objects from the classroom instead of printed materials.
Preparation. Make faulty circuits.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Show an unlit lamp and ask, “Why is it off?”
Explanation (10 min). Teach open and closed.
Guided activity (10 min). Learners trace.
Independent activity (10 min). Learners fix.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Is the loop complete?
Teacher explanation notes. Start with real objects and safe, hands-on observation. Then talk about what was seen, then draw and write. Always say “how do you know?”. Keep to the safety notes, and use local, safe materials.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and pictures, short sentences and a partner. Let learners point, show or draw instead of writing. Extension. Ask learners to find a new example at home and explain how they know.
Formative assessment. Listen to learners read and explain, ask “how do you know?”, and check the independent work.
Misconceptions. “Current is used up by the lamp.” It flows around.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz, the 10-mark exam practice and the worksheet on this page. All answers and marking guides are in the answer sections above. Re-check every answer before use.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Explain open and closed circuits. Enrichment. Look for one new example near your home or school, draw it and explain it to someone. Homework. See above.
Teacher reflection. After teaching, record: which ideas learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points: Next Generation Science Standards, Cambridge Primary Science and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Research used to shape this lesson. Courseversity Science curriculum, Grade 4 Unit 6, topic 8; Next Generation Science Standards, energy; Cambridge Primary Science Stage 4, physics: electricity; IB Primary Years Programme, how the world works. These sources informed the lesson.