IGCSE›Cambridge IGCSE Physics›Mind mapsReflection of LightCambridge IGCSE Physics: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsKey termsNormal is perpendicular to the surfaceAngle of incidence is between incident ray and normalAngle of reflection is between reflected ray and normalIncident ray comes in; reflected ray bounces awayLaw of reflectionAngle of incidence equals angle of reflectioni=ri = ri=rIncident ray, reflected ray and normal share one planeWorks for mirrors, still water, polished metalHits at 0° → reflects straight backReflectionbouncing light off mirrorsi = rPlane mirror imageSame size as the objectSame distance behind mirror as object in frontVirtual so cannot be put on a screenUpright but laterally reversedRays traced backwards appear to meet behind mirrorConstructing raysDraw the mirror, then the normal at 90°Measure i with a protractor from the normalDraw reflected ray at equal angle on opposite sideObject 12 cm away → image 12 cm behind, 24 cm apartExam tipsMeasure angles from the normal, never the mirrorAlways draw the normal firstSay 'same size, same distance, virtual'Normal must be at 90° whatever the mirror's tilt