A ray of monochromatic light passes from medium (1) to medium (2). If the angle of incidence in medium (1) is θ and the corresponding angle of refraction in medium (2) is θ/2, which of the two media is optically denser? Give reason. [Foreign 2013]
Answers
When the light ray passes from
an optically lighter to denser medium, the light ra y bends towards the normal to the interface at the point of incidence. That means that the angle of refraction is less in the denser medium.
In the given example, medium 1 is the lighter one and medium2 is denser.
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The actual reason for the bending of light ie., angle of refraction being smaller than angle of incidence is because of speed of light being less in a denser medium. Light rays travel with less speed due to optical resistance faced.
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formula wise, μ₁ sin i = μ₂ sin r
i = x > r = x/2, so μ₂ > μ₁
so medium 1 is lighter as refractive index is less. Refractive index of vacuum (lightest) is 1 and all other media have that more than 1.
mark as brillienst answer