Physics Paper 1 · P2 · Lesson 2.7
Remember one clear behaviour for each component.
A diode allows current mainly in one direction. It has a very high resistance in reverse. An LED is a diode that emits light when current flows in the forward direction.
The LED symbol has two arrows pointing outwards.
No timer. Read the explanation after each answer.
Daily 5 · Exam practice · Extra calculation practice · A4 revision sheet
Start with lessons 2.1–2.6 for the circuit basics. Lesson 2.15 offers extra calculation practice. The P2 specification content is shared by Foundation and Higher Tier; extra practice is not Higher Tier-only.
AQA Combined Science Trilogy specification · 6.2.1.1; 6.2.1.4. Original notes, questions and diagrams. Circuit animations are simplified; motion is deliberately slowed. Measurements and example values are illustrative. All practical circuits use suitable supervised low-voltage apparatus.
Photographs: Photograph of the inside of a UK plug by Alby Reid, Public domain, released by the copyright holder; Electricity pylons near Grafham Water by Mat Fascione, CC BY-SA 2.0; Photoresistor 2 by oomlout, CC BY-SA 2.0. Images displayed without cropping or alteration.
