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Question
- Explain why the refractive index of any material with respect to air is always greater 1.
- In the figure below a light ray travels from air into the semi-circular plastic block. Give a reason why the ray does not deviate at the semi-circular boundary of the plastic block.
- Complete the ray diagram of the above scenario when the light ray comes out of the plastic block from the top flat end.
Solution
- The refractive index of a medium with respect to air is given by `"speed of light in the air"/"speed of light in the medium"`. Since the speed of light in the medium is always less than the speed of light in air, hence the above ratio is always greater than 1.
- The ray of light is undergoing normal incidence at the air-plastic block interface. And for normal incidence, there is no deviation.
(Credit arrows, refracted ray moving away from normal)
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Mark the correct answer in the question.
If the refractive index of glass with respect to air is 3/2, what is the refractive index of air with respect to glass?
Refractive index of air : 1.0003 : : refractive index of water : _______
