MHT CET202124 Sep 2021Evening ShiftPhysicsRay OpticsActual
A ray of light is incident on one face of an equilateral glass prism having refractive index 2 . It produces the emergent ray which just grazes along the adjacent face. The value of angle of incidence is
Options
- A⁻¹ ( 1 2 15^ )
- B⁻¹ ( 2 30^ )
- C⁻¹ ( 1 2 45^ )
- D⁻¹ ( 2 15^ )
Correct answer
D. ⁻¹ ( 2 15^ )
Step-by-step solution
The emergent ray just grazes the second face. Hence angle of emergence, e =90^ aligned & = e r₂ = 90^ r₂ = 1 r₂ & 1 r₂ = 2 or r₂= 1 2 aligned aligned & r ₂=45^ ; A = r ₁+ r ₂ & r ₁= A - r ₂=60-45=15^ aligned Also, i r₁ = aligned & i = r ₁= 2 15^ & i = ⁻¹ ( 2 15^ ) aligned