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MHT CET 2026 (11 Apr, Shift 2) · Prism, Dispersion & Scattering

Prism, Dispersion & Scattering question from MHT CET 2026 (11 Apr, Shift 2)

Q10MHT CET 2026 · 11 APR · SHIFT 2Medium

Prism, Dispersion & Scattering

A thin prism in air produces the angle of minimum deviation δ\delta. If the prism is immersed in water, the angle of minimum deviation for the same ray is (refractive index of water is 4/34/3 and that of glass prism is 3/23/2)

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Answer: (c)

  1. Thin prism: δ=(nrel−1)A\delta = (n_{\text{rel}} - 1)A
  2. In air: δ=(32−1)A=A2\delta = \left(\frac{3}{2} - 1\right)A = \frac{A}{2}
  3. In water: nrel=3/24/3=98n_{\text{rel}} = \frac{3/2}{4/3} = \frac{9}{8}, so δ′=A8\delta' = \frac{A}{8}
  4. δ′δ=14\frac{\delta'}{\delta} = \frac{1}{4}, so the answer is (c) δ4\frac{\delta}{4}.
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