Physics Circle home Student Login

Home›Chapters›Ray Optics PYQs›Prism, Dispersion & Scattering›Question 75

JEE Main 2018 (16 Apr, Shift 1) · Prism, Dispersion & Scattering

Prism, Dispersion & Scattering question from JEE Main 2018 (16 Apr, Shift 1)

Q75JEE Main 2018 · 16 APR · SHIFT 1Medium

Prism, Dispersion & Scattering

A ray of light is incident at an angle of 60° on one face of a prism of angle 30°. The emergent ray of light makes an angle of 30° with incident ray. The angle made by the emergent ray with second face of prism will be:

Show answer and solution

Answer: (b)

  1. Deviation δ=i+e−A\delta = i + e - A
  2. 30∘=60∘+e−30∘⇒e=0∘30^\circ = 60^\circ + e - 30^\circ \Rightarrow e = 0^\circ
  3. The emergent ray leaves along the normal to the second face, so it makes 90∘90^\circ with that face.
  4. So the answer is (b) 90∘90^\circ.
Report a mistake

More questions on Prism, Dispersion & Scattering