GCSE›Edexcel GCSE Physics›Mind mapsOpticsEdexcel GCSE Physics: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsReflectionAngle of incidence = angle of reflectionBoth measured from the normalSpecular: smooth surface, one directionDiffuse: rough surface, scatteredRefractionDirection and speed change between substancesCaused by a change in wave speedInto glass: bends towards the normalOut of glass: bends away from the normalTotal internal reflectionDense to less dense substanceAngle above the critical angleAll light reflects backOpticslight and lensesnnnfColourOpaque objects reflect their own colourRed object absorbs all other coloursFilter transmits only certain wavelengthsLensesConverging (convex) brings rays togetherConverging: real or magnified virtual imageDiverging (concave) spreads rays apartDiverging: virtual upright diminished imageShorter focal length means higher powerExam tipsMeasure angles from the normalDiverging lens never forms a real image