Physics
The refractive index of glass is 1.5. From a point P inside a glass slab, draw rays PA, PB and PC incident on the glass-air surface at an angle of incidence 30°, 42° and 60° respectively.
(a) In the diagram show the approximate direction of these rays as they emerge out of the slab.
(b) What is the angle of refraction for the ray PB?
(Take sin 42° = 2 / 3)
Refraction Plane Surfaces
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Answer
(a) Diagram with rays PA, PB and PC is shown below:
(b) Given,
μg = 1.5
As we know,
Substituting the values in the formula we get,
Hence, we can round off ic = 42°
Applying,
Given,
and
Substituting the values in the formula we get,
As sin r = 1 , so angle of refraction = 90°.
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