lecture notes on light

angle of incidence angle of refraction aperture appear arranged body bright called candle centre centre of curvature circle coincide colour combination concave lens concave mirror converge convex lens critical angle crystalline lens dark diagram direction displacement distance diverge drawing drew earth eclipse edge emergent equal experiment focal length formed formula front gives glass greater illumination incident ray inverted joined lamp lenses less light looking magnified means measured medium method nearly needle normal notes object observed obtained optical parallel pass pencil photometer piece pins placed plane plate position principal axis principal focus prism produced radius real image reflected ray refraction retina screen seen shadow side spectrum standard surface telescope took totally reflected transmitted travels turned usual virtual image