Science 7 - LAND and SEA BREEZE and its Characteristics
5.2 Refraction
1. (denser) (less dense) 5.2 Refraction of Light When light travels through two materials of different optical densities , it will change direction at the boundary between them. In other words, it changes speed and bends . How is light refracted ?
2. i r Normal Incident ray Angle of incidence refracted ray Angle of refraction Medium 1 Medium 2 Angle between incident ray and normal Line perpendicular to the boundary Angle between refracted ray and normal Original path of light ray Important Terminologies
3. Bending of the Light Normal Air Glass Normal Air Glass Light is not bent when it travels along the normal. Light bends towards normal when it enters an optically denser medium . However, light bends away from normal when it enters an optically less dense medium . Bends towards the normal Bends away from the normal
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7. Example 2 (a) Air Crown glass Normal 30 o r Calculate the angle of refraction in crown glass. n =1.52 (b) Air water Normal 60 o i Calculate the angle of incidence in water. n =1.33 Solution (a) (b)
8. Real depth, H and apparent depth, h The legs appear to be shorter than their actual length in a pool. Why ?
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10. Relationship between real depth, H and apparent depth, h Refractive index , Apparent depth, h / cm Real depth, H / cm O
