StemSphere
Start learning
Home/Lessons/Simple Electric Circuits
Basic Technology

Simple Electric Circuits

Electric current flows only when components form a complete conducting path. This lesson uses familiar circuit symbols and simple troubleshooting.

JSS 2–325 minInteractive quizOffline-ready
Simple Electric Circuits lesson illustration
Basic Technology • JSS 2–325 min • self-paced
Learning objectives

By the end of this lesson, you should be able to:

  • Identify the cell, bulb, switch and connecting wire.
  • Distinguish an open circuit from a closed circuit.
  • Compare series and parallel circuits.
  • Classify conductors and insulators.
  • Follow basic electrical safety rules.
Core idea

A complete path

An electric circuit is a complete path through which electric current can flow from a source, through components, and back to the source.
Closed circuit

The path is complete

Current flows and a correctly connected bulb can light.

Open circuit

The path is broken

Current cannot flow, so the bulb does not light.

Circuit parts

Know each component

🔋
Cell or battery

Provides electrical energy and potential difference.

💡
Lamp

Converts electrical energy into light and heat.

🎚️
Switch

Opens or closes the conducting path.

➰
Wire

Connects components and carries current.

🛡️
Fuse

Breaks the circuit if current becomes dangerously high.

🔔
Buzzer

Converts electrical energy into sound.

Circuit arrangement

Series and parallel circuits

Series

One path

All components share one route. If one bulb is removed, the whole circuit is broken.

Parallel

More than one path

Branches allow components to work independently. Homes are wired mainly in parallel.

Test materials

Conductors and insulators

Conductors allow electric current to pass easily. Examples include copper, aluminium and graphite.
Insulators resist current. Examples include dry plastic, rubber, glass and ceramic.
Investigation: use only a low-voltage cell circuit under supervision—never use wall electricity for a classroom test.
Stay safe

Electrical safety

  • Keep water awayWet skin and water can increase the risk of electric shock.
  • Do not overload socketsToo much current can overheat wires and cause fire.
  • Replace damaged cablesExposed conductors are dangerous.
  • Use the correct fuseA fuse is a safety device, not an inconvenience to bypass.
Mother-tongue reinforcement

Review the main idea

English summary

A circuit must form a complete path before current can flow. Series circuits have one path, while parallel circuits have branches. Metals are usually conductors, while plastic and rubber are insulators.

Question 1 of 5

Assignment

Apply your understanding

  1. Draw a labelled circuit containing one cell, one switch and one bulb.
  2. State two differences between series and parallel circuits.
  3. List four conductors and four insulators found around you.
← Previous lessonBrowse all lessons →