This memory aid covers Memory Aid within Resistance & Ohm's Law for GCSE Physics. Revise Resistance & Ohm's Law in Electricity for GCSE Physics with 16 exam-style questions and 30 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 12 of 16 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
🧠 Memory Aid
VIR Triangle — "Very Important Relationship":
Write V at the top, I and R at the bottom. Cover the letter you want to find: V on top alone = I × R; I on bottom-left = V ÷ R; R on bottom-right = V ÷ I.
Non-ohmic components — "FDT Changes":
Filament lamp, Diode, Thermistor — these three all have changing resistance. Everything else (fixed resistors) is ohmic.
Thermistor vs LDR — "Hot is Less, Bright is Less":
Hotter thermistor = less resistance. Brighter LDR = less resistance. Both sensors work the same way — the thing they detect reduces their resistance.
Wire resistance factors — "LAMT":
Length (more = more R), Area (more = less R), Material, Temperature.
Practice questions for Resistance & Ohm's Law
Which of the following best describes electrical resistance?
Explain what is meant by an ohmic conductor.