GCSE›AQA GCSE Physics›Mind mapsCurrent, Potential Difference and ResistanceAQA GCSE Physics: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsCurrentRate of flow of charge, measured in amperesQ=ItQ = ItQ=ItCharge in coulombs, time in seconds2 A for 5 s transfers 10 CPotential differenceEnergy transferred per unit chargeV=WQV = \frac{W}{Q}V=QW1 volt = 1 joule per coulomb12 V across 5 C transfers 60 JCurrent, pd, Rcharge, energy, oppositionAVΩCResistanceOpposition to current, measured in ohmsV=IRV = IRV=IRSame pd: higher RRR gives lower currentOhmic conductor has constant resistanceTemperatureMetal resistance rises as it heats(HT) Ions vibrate more in the lattice(HT) Electrons collide more often with ions(HT) More collisions mean less currentExam tipsWrite the equation, substitute with units, then answerShow the rearrangement step every timeIn multi-part questions reuse your answer from part (a)