The idea
Circuit diagrams are a shared language. Draw the symbol, not a picture of the battery.
| Component | Job |
|---|---|
| Cell / battery | Supplies potential difference |
| Switch | Opens or closes the path |
| Resistor | Limits current |
| Lamp | Converts electrical energy to light and heat |
| Ammeter | Measures current — wired in series |
| Voltmeter | Measures potential difference — wired in parallel |
graph LR BAT["Battery +/-"] --> SW["Switch"] SW --> R["Resistor"] R --> L["Lamp"] L --> BAT
Meters go in different places, and it matters
An ammeter must be in the path so all the current passes through it. A voltmeter goes across a component to compare two points.
Put an ammeter across a battery and you have created a short circuit with a very expensive fuse in it. Ask me how the department knows.
Drawing conventions
- Straight lines, right angles, no diagonal spaghetti.
- Components spaced evenly along the sides of a rectangle.
- Label every component with its value: , .
Practise at Circuit Diagram Practice.
Curriculum connection
D2.3
identify the components of a direct current (DC) circuit and explain their functions, and identify electrical quantities, their symbols, and their corresponding International System of Units (SI) units
Link to original