A circuit diagram is a kind of writing, each squiggle a known component. Learn the alphabet, and a tangle of wires on the bench becomes a clear, readable plan.
Components are drawn with standard symbols. A light-dependent resistor has a low resistance in bright light, a thermistor has a low resistance when hot, a relay uses a small current to switch a larger one, and a diode allows current in one direction only.
Circuits are drawn with standard circuit symbols. A light-dependent resistor (LDR) has a lower resistance in bright light; a thermistor has a lower resistance when hot.
A relay uses a small current to switch a larger circuit; a diode allows current one way only.
Match each symbol to its component and see how the input transducers respond.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
In bright light, the resistance of an LDR is...
When a thermistor is hot, its resistance is...
A relay is a component that...
Which component allows current to pass in one direction only?
Some components simply pass current; others sense light or heat, or switch and steer the current.
An LDR has a high resistance in the dark and a low resistance in bright light. A thermistor has a high resistance when cold and a low resistance when hot. It is easy to state both the wrong way round.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
Which component would be used as a light sensor in a circuit?
On a cold day, the resistance of a thermistor is...
A small sensor current needs to switch a powerful motor on and off. The component for this is a...
Circuit symbols and components are mapped. Keep the chain going.