LDRs and Thermistors: Resistance That Changes | GCSE Physics

LDRs and thermistors for GCSE Physics, animated: the circuit symbols, why an LDR's resistance falls as the light gets brighter, why an NTC thermistor's resistance falls as it gets hotter (the opposite of a filament lamp), and the resistance-light and resistance-temperature graphs. How to measure their resistance with an ammeter in series and a voltmeter in parallel, then a worked example with V = IR: a thermistor on a 6 V supply at 3 kΩ and 600 Ω. Finishes with AQA's two uses, a thermostat and a light that switches on when it gets dark. Covers: AQA 4.2.1.4 (Combined 6.2.1.4) · Edexcel Topic 10 (10.19–10.21) · OCR Gateway P3.2 (Foundation and Higher, Combined and separate Physics). 0:00 Intro 0:08 Hook 0:45 The LDR 1:21 The thermistor 2:15 Measuring the resistance 3:09 Worked example 4:25 Uses: thermostat and dark-activated light 5:19 Summary Narrated with an AI voice. Worked Example is not affiliated with or endorsed by AQA, OCR or Pearson Edexcel. Exam board names are used only to show which specifications a video covers.