Year 6 science · Key Stage 2 · Electricity

Year 6 electricity: circuits, components and circuit symbols

In Year 6, children go further with the simple series circuits they built in Year 4. They link the brightness of a lamp or the loudness of a buzzer to the number and voltage of the cells, explain why components behave differently, and draw circuits using standard symbols instead of pictures. Only series circuits are expected at this stage.

Circuit components and symbols, explained

A series circuit is a single loop containing a power source and components, such as lamps, buzzers, motors and switches, joined by wires. For anything to work, the loop must be complete with no gaps. In school, children learn to say “cell” for what everyday speech calls a battery. A battery is strictly two or more cells joined together. A cell pushes the electricity round the circuit, and the size of that push is its voltage, measured in volts. A typical cell in a school kit has a voltage of 1.5 volts.

The Year 6 idea is that changing the number or voltage of the cells changes what the components do. In a circuit with one lamp, adding a second cell (facing the same direction) makes the lamp brighter. In the same way, a buzzer gets louder as more cells are added, and a motor turns faster. Taking cells away has the opposite effect. Too much voltage can damage a lamp, which is why lamps are chosen to suit the cells. Children compare and explain the effects, and they change one thing at a time so the test stays fair. They aren’t expected to measure the current or calculate anything.

Children also compare components and explain what they do. A switch controls a circuit by opening or closing the loop: when it is closed the loop is complete and the lamp lights, and when it is open there is a gap and nothing works. In a series circuit, it does not matter where the switch is placed, because the loop is broken wherever the gap is. A lamp that doesn’t light might have a loose wire, a flat cell or a broken filament, and a cell placed the wrong way round can cancel another. Children learn to fault-find by checking one thing at a time.

The third strand is drawing circuits with recognised symbols. Instead of drawing a picture of a battery pack and a bulb, children draw a cell as one long line and one short line, a lamp as a circle with a cross, a motor as a circle with an M, a switch as a break in the wire with a hinged arm, and wires as straight lines with square corners. Symbols mean anyone, anywhere, can read the diagram. Safety is part of the topic: children learn to use low-voltage cells only and never to play with mains sockets.

Words your child will hear

Cell: A single unit that provides the energy for a circuit. A battery is two or more cells joined together.
Voltage: A measure, in volts, of how big a push a cell or battery gives to the electricity in a circuit.
Component: Any part of a circuit, such as a lamp, buzzer, motor or switch.
Series circuit: A circuit in which everything is joined in one single loop.
Switch: A component that opens or closes a circuit. When it is closed the circuit is complete.
Conductor and insulator: Conductors, such as metal wire, let electricity pass through. Insulators, such as plastic, do not.
Circuit symbol: A standard simple drawing used to stand for a component in a circuit diagram.

What the National Curriculum says

In Year 6, pupils should be taught to:

Associate the brightness of a lamp or the volume of a buzzer with the number and voltage of cells used in the circuit
Compare and give reasons for variations in how components function, including the brightness of bulbs, the loudness of buzzers and the on/off position of switches
Use recognised symbols when representing a simple circuit in a diagram

Objectives from the National Curriculum in England, © Crown copyright, used under the Open Government Licence v3.0.

Try it: drawing and testing a circuit

Draw a circuit with two cells, a lamp and a switch using symbols, then predict and test what happens to the lamp when you add the second cell.

List the components: two cells, one lamp, one switch and wires. Plan a single loop.
Draw the loop with a ruler, with straight lines and square corners. Put each symbol in a gap in the wire: two cells (long and short lines, facing the same way), a lamp (a circle with a cross), and a switch (a break with a hinged arm). A rough plan of the layout:
```
  +------[ switch ]------+
  |                      |
[ 2 cells ]            ( X ) lamp
  |                      |
  +----------------------+
```
Predict. “With the switch closed, the loop is complete, so the lamp will light. I think it will be brighter with two cells than with one, because two cells give a bigger voltage.”
Test fairly. Build the circuit with one cell and note the brightness (for example dim, medium, bright). Change only the number of cells, adding the second cell the same way round. Keep the same lamp and wires. Open the switch and check the lamp goes out.
Explain. The lamp is brighter with two cells because the voltage is greater, so more electricity is pushed round the circuit. The lamp goes out when the switch is open because the gap breaks the loop.

The lamp lights when the switch is closed, is brighter with two cells than with one, and goes out when the switch is opened. A bigger voltage makes the lamp brighter, and a gap anywhere in a series circuit stops everything working.

Common mistakes and how to help

Thinking electricity gets used up as it goes round the circuit

The lamp seems to take something from the cell, so children imagine less being left after it.

What helps: Explain that the lamp transfers energy from the cell as light and heat, but the electricity itself keeps flowing all the way round the loop. It is not used up on the way.

Believing the switch only works if it is next to the cell

Children expect the switch to control the electricity at its source, like a tap.

What helps: Move the switch to another part of the loop. It still turns the lamp off, because it breaks the loop wherever it is.

Drawing circuits as pictures, or with curved wires and gaps

Children naturally want to draw what the equipment looks like.

What helps: Introduce the symbols as a shorthand that everyone shares. Use a ruler and check that the loop in the diagram is unbroken, with no gaps apart from a switch.

Thinking more cells will always give a better result

More cells made the lamp brighter, so children assume the pattern carries on for ever.

What helps: Explain that lamps are designed for particular voltages, and too many cells can make them burn out. Cells must also be placed facing the same direction to add together.

How to help at home

Torch investigation. With an adult, take the batteries out of a battery-powered torch and look at how the cells, switch and bulb (or LED) are joined. Sketch it using circuit symbols. Never take apart anything plugged into the mains.
Switch and circuit hunt. Look for items that run on small cells, such as a toy, a remote control or a clock. Find where the cells go and think about how a switch controls the flow. Keep small round button batteries well away from younger children, as they are very dangerous if swallowed.
Draw it with symbols. Ask your child to draw a circuit for a doorbell or an alarm with a cell, a buzzer and a switch, using symbols and a ruler. Check that the loop is complete and the switch can break it.
Safe-electricity talk. Repeat the safety rules: use only small cells for experiments, never touch or poke at mains sockets, never put wires into a socket, and never connect the two ends of a cell with a single wire, as it gets hot.
Design a traffic light. Plan on paper a model traffic light made from three separate simple circuits, each with its own cell, lamp and switch, and draw each circuit with symbols. A burglar alarm with a buzzer and a switch is another good design. If you already have a cell holder, a small bulb and some wire, building one of the circuits brings the plan to life.

Leads on to

Key Stage 3: Current, voltage and resistance
Key Stage 3: Static electricity and electric fields
Key Stage 3: Magnetism and electromagnets

Everything in Year 6 science

Updated 20 October 2026.