NEET2019PhysicsRay OpticsActual
Find the value of in the given diagram.
Options
- A⁻¹ ( 2 3 )
- B⁻¹ ( 1 3 )
- C⁻¹ ( 1 2 )
- D⁻¹ ( 1 2 )
Correct answer
B. ⁻¹ ( 1 3 )
Step-by-step solution
Key Idea The angle of incidence in a denser medium for which the angle of refraction in rarer medium becomes 90^ is known as critical angle. C = ⁻¹ 1 where, = refractive index of denser to rarer medium. Since, BC grazes along sarface aligned & angle (90- ₁ )= critical angle C & C= 1 & (90- ₁ )= 3 2 ₁= 3 2 & ₁=30^ & aligned Now, using Snells' law on lst interface, array rlrl n ₁ & = n ₂ ₁ & & 1 = 2 3 30^ & = 2 3 1 2 & & & = 1 3 & & & = ⁻¹ ( 1 3 ) array