2.1.1 Circuit Diagrams

• Basic Symbols and Components

  • Cell (Battery)
  • Resistor
  • Conductor/Wires
  • Switch
  • Lamp (Light Bulb)
  • Fuse
  • Capacitor
  • Diode
  • Transistor
• Cell (Battery)


  Provides electrical energy
• Resistor


  Limits the flow of current and can be used to control voltage within a circuit
• Conductor/Wires

  Allows electrical current to flow between components
• Switch


  Opens or closes the circuit to start or stop the flow of current
• Lamp (Light Bulb)

  Converts electrical energy into light
• Fuse

  Protects the circuit by breaking the connection if the current is too high
• Capacitor


  Stores and releases electrical energy
• Diode

  Allows current to flow in one direction only
• Transistor


  Acts as a switch or amplifier
• Reading Circuit Diagrams

  1. Identify components

  2. Trace the circuit

  3. Understand connections

  4. Analyze function
• Series Circuit


  • Components connected end-to-end
  • Current flows through each component one after another
• Parallel Circuit


  • Components connected across the same two points
  • Current splits and flows through multiple paths
• Example Circuits

  • Simple Series Circuit
  • Simple Parallel Circuit
  • Circuit with a Switch
• Simple Series Circuit
• Simple Parallel Circuit
• Circuit with a Switch
• Designing Circuits

  Use circuit diagrams to plan and design electrical circuits
• Troubleshooting

  Use circuit diagrams to diagnose problems in a circuit
• Building Circuits

  Follow circuit diagrams to assemble physical circuits
• Practice and Application


  1. Draw and interpret diagrams

  2. Use simulation tools

  3. Conduct hands-on experiments
• Key Points to Remember