Changing circuits

I can use circuit symbols and explain why a bulb gets brighter or dimmer, or a buzzer louder or quieter.

For grown-ups: this lesson in words

Year 6 · Science

Scientists draw circuits with simple symbols instead of pictures. This is a circuit diagram.
A cell is drawn as a long thin line next to a short thick line.
Straight lines stand for the wires that join the parts in a loop.
A circle with a cross in it is a bulb, also called a lamp. The loop is complete, so the bulb lights.
Picture: A drawing of a circuit diagram drawn with symbols. The loop is complete, so the bulb lights. Labels: cell, wire and bulb.
This loop has the cell and the bulb you know, and three more symbols.
A switch is a short line between two small rings. This switch is closed: its line touches both rings.
A buzzer is drawn as a half circle.
A motor is a circle with the letter M inside it.
Picture: A drawing of a circuit diagram drawn with symbols. The loop is complete, so the bulb lights. Labels: switch, buzzer and motor.
Your turn: In this circuit diagram, one symbol has a ? instead of its name. It is a circle with a cross inside. Which part does it stand for?
Picture: A drawing of symbols joined by straight lines in a loop. The lines make a complete loop. Labels: cell and wire. A label marked ? points to the circle with a cross in it, at the top of the loop.
Choose one:
- Motor
- Bulb
- Buzzer
Answer
The answer: Bulb
It is a bulb, also called a lamp. Its symbol is a circle with a cross in it.
Picture: A drawing of a circuit diagram drawn with symbols. The loop is complete, so the bulb lights. Labels: cell, wire and bulb.

symbol:: A simple drawing that stands for one part of a circuit.
circuit diagram:: A drawing of a circuit made with symbols joined by straight lines.
cell:: One part that pushes electricity round a circuit. Its symbol is a long and a short line.
battery:: Two or more cells joined together.
voltage:: How hard the cells push electricity round a circuit. It is measured in volts, written V.

This is the first part of the lesson. Grown-ups can unlock every lesson in the grown-ups area.