CBSE Class 12 · 2020 · Geometrical OpticsVery Short Answer

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A ray of light on passing through an equilateral glass prism suffers a minimum deviation equal to the angle of the prism. The value of the refractive index of the material of the prism is \underline{\hspace{2cm}}.

Answer: $3 (\approx 1.732)$ .

Solution

For an equilateral prism

A = 6 0^{\circ}

and here

δ_{m} = A = 6 0^{\circ}

μ = \frac{sin ( \frac{A + δ _{m}}{2} )}{sin ( \frac{A}{2} )} = \frac{sin 6 0 ^{\circ}}{sin 3 0 ^{\circ}} = \frac{\frac{3}{2}}{\frac{1}{2}} = 3

CBSE Class 12 Board · 2020 · Subjective

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