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Refraction of Light1. Meaning : - is the bending of light when it travels from one medium to another medium of different (optical) density.2. Is due to the different speeds of light in the

two medium.3. Light is not refracted when it enters a

medium at right angle (perpendicular to the medium)

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4. Law of Refraction

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5. Refractive Index (Indeks Biasan), n

a) Is defined as :

‘ ratio of sinus of incidence angle to sinus of refractive

angle’

n = sin i [ i = incidence angle (sudut tuju) ]

sin r [ r = refractive angle (sudut biasan) ]

b) n is also shows the different speed of light in two mediums as :

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c) Table below shows refractive index of different materials :

d) Refractive index shows the density of medium compared to air.

When n > 1.00, the medium is denser than air.

e) The larger the refractive index, the slower the speed of light in the

medium

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7. Examples : a) The speed of light in glass is 2.0 x 108 m s-1 and the speed of light in air is 3.0 x 108 m s-1. Calculate the refractive index of the glass. b) The refractive index of water is 1.3. What is the speed of light in water if its speed in air is 3.0 x 108 m s-1?

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7. Examples : c) Figure below shows light ray travels from air to glass at an angle of incidence, θ= 60o.

Calculate the : i) angle of refraction, r. ii) speed of light in water if refractive index of water is 1.33 and speed of light in air = 3 x 108 m s-1 .

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