Physics Circle home Student Login

Home›Chapters›Ray Optics PYQs›Prism, Dispersion & Scattering›Question 21

JEE Main 2025 (23 Jan, Shift 2) · Prism, Dispersion & Scattering

Prism, Dispersion & Scattering question from JEE Main 2025 (23 Jan, Shift 2)

Q21JEE Main 2025 · 23 JAN · SHIFT 2Medium

Prism, Dispersion & Scattering

The refractive index of the material of a glass prism is 3\sqrt{3}. The angle of minimum deviation is equal to the angle of the prism. What is the angle of the prism?

Show answer and solution

Answer: (a)

  1. With δm=A\delta_m = A: μ=sin⁡Asin⁡A2=2cos⁡A2\mu = \dfrac{\sin A}{\sin\frac{A}{2}} = 2\cos\frac{A}{2}
  2. 3=2cos⁡A2⇒cos⁡A2=32⇒A2=30∘\sqrt{3} = 2\cos\frac{A}{2} \Rightarrow \cos\frac{A}{2} = \frac{\sqrt{3}}{2} \Rightarrow \frac{A}{2} = 30^\circ
  3. So the answer is (a) 60∘60^\circ.
Report a mistake

More questions on Prism, Dispersion & Scattering