A ray is incident at an angle of incidence i on one surface of a small angle prism (with angle of prism A ) and emerges normally from the opposite sur - Physics MCQ NEET 2020 E1 2026 | ExamTest.live

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A ray is incident at an angle of incidence on one surface of a small angle prism (with angle of prism ) and emerges normally from the opposite surface. If the refractive index of the material of the prism is , then the angle of incidence is nearly equal to:

Solution & Step-by-step Explanation

Emerges normally means angle of emergence e = 0 .In a prism, r_{1} + r_{2} = A . Since e = 0, r_{2} = 0, so r_{1} = A .Applying Snell's law at the first surface: sin i = μ sin r_{1} .For small angles, sin θ \approx θ . i \approx μ r_{1} \Rightarrow i \approx μ A

Try it yourself before checking the explanation above.

A ray is incident at an angle of incidence on one surface of a small angle prism (with angle of prism ) and emerges normally from the opposite surface. If the refractive index of the material of the prism is , then the angle of incidence is nearly equal to:

\frac{A}{2 μ}

\frac{2 A}{μ}

μ A

\frac{A}{2} μ

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