JEE Mains · Physics · STD 12 - 9. Ray optics and optical instruments
Consider an equilateral prism (refractive index \( \sqrt{2} \)). A ray of light is incident on its one surface at a certain angle i. If the emergent ray is found to graze along the other surface then the angle of refraction at the incident surface is close to __________ .
- A \( 15^{\circ} \)
- B \( 20^{\circ} \)
- C \( 40^{\circ} \)
- D \( 30^{\circ} \)
Answer & Solution
Correct Answer
(A) \( 15^{\circ} \)
Step-by-step Solution
Detailed explanation
Equilateral prism. \( A=60^{\circ} \) \( \mu~Sinr_{2}=1.sine=1 \) \( Sinr_{2}=\frac{1}{\mu}=\frac{1}{\sqrt{2}} \) \( r_{2}=45^{\circ} \) \(\therefore r_1=A-r_2=15^{\circ}\)
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