Overview
This lesson introduced the differences between series and parallel electrical circuits, focusing on how current, voltage, and resistance behave in each setup.
Basic Circuit Concepts
- A circuit is a complete path that allows electric current to flow.
- A power source (like batteries or cells) provides the energy for the circuit.
- Conductors (usually metal wires) carry the current.
- The load (such as a bulb) uses the electricity.
- An open circuit means there is a gap, so no current flows.
- A closed circuit is a complete loop that allows current to flow.
- Current is the flow of electric charge through a circuit.
- Voltage is the energy that pushes electric charges through a circuit.
- Resistance slows down the flow of electric current.
Circuit Boards
- Circuit boards connect components using tracks instead of wires.
- Components include holders for torch cells (batteries), metal pegs, conducting strips, bulbs, resistors, LEDs, and capacitors.
- Up to three torch cells can be placed in series on the holder.
- Crocodile clips can connect cells to wires on the board.
- Circuit boards are found in electronic devices like TVs and microwaves.
Series Circuits
- Series circuits have only one path for current to flow.
- The same current flows through all components.
- Voltage is shared between components.
- If one component breaks, the whole circuit stops working.
- Resistance increases as more components are added.
- More resistance means dimmer bulbs.
Parallel Circuits
- Parallel circuits have multiple paths (branches) for current to flow.
- Each component gets the full voltage.
- If one bulb breaks, others stay on.
- The current splits between branches.
- Total resistance decreases as more branches are added.
- More branches mean brighter bulbs.
Comparing Series and Parallel Circuits
- In series, current is the same throughout; in parallel, current divides among branches.
- In series, voltage is shared; in parallel, each branch receives full voltage.
- In series, resistance increases with components; in parallel, resistance decreases with more branches.
Resistance and Materials
- High resistance metals: tungsten, nichrome.
- Low resistance metals: gold, copper, silver, aluminum.
Key Terms & Definitions
- Circuit — a complete path for electric current.
- Power Source — provides energy (like a battery).
- Conductor — material that allows current to flow (metal wires).
- Load — component that uses electricity (bulb).
- Open Circuit — incomplete path, no current flows.
- Closed Circuit — complete loop, current flows.
- Current — flow of electric charge.
- Voltage — energy pushing charges through a circuit.
- Resistance — slows down electric current.
- Series Circuit — one path, shared voltage.
- Parallel Circuit — multiple paths, each gets full voltage.
Action Items / Next Steps
- Review differences between series and parallel circuits.
- Test knowledge with the self-marking quiz (link provided in lesson).
- Prepare for the next lesson on visible light.