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The diagram below shows a light source P embedded in a rectangular glass block ABCD of critical angle 42°. Complete the path of the ray PQ till it emerges out of the block. [Write necessary angles].

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Question

The diagram below shows a light source P embedded in a rectangular glass block ABCD of critical angle 42°. Complete the path of the ray PQ till it emerges out of the block. [Write necessary angles].

Diagram
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Solution

Given, critical angle, C = 42°

At a point Q, i = 48° and iC = 42°

i.e. i > iC

r = 48°

At a point P, i = 42° and iC = 42°

i = iC

Therefore, r = 90°

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Chapter 4: Refraction of Light at Plane Surfaces - EXERCISE - 4 (D) [Page 102]

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Selina Concise Physics Part 2 [English] Class 10 ICSE
Chapter 4 Refraction of Light at Plane Surfaces
EXERCISE - 4 (D) | Q 31 | Page 102

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