JEE Advanced2025PhysicsRay OpticsActual
Two identical concave mirrors each of focal length f are facing each other as shown in the schematic diagram. The focal length f is much larger than the size of the mirrors. A glass slab of thickness t and refractive index n₀ is kept equidistant from the mirrors and perpendicular to their common principal axis. A monochromatic point light source S is embedded at the center of the slab on the principal axis, as shown
Options
- A4 f+ (1- 1 n₀ ) t
- B2 f+ (1- 1 n₀ ) t
- C4 f+ (n₀-1 ) t
- D2 f+ (n₀-1 ) t
Correct answer
A. 4 f+ (1- 1 n₀ ) t
Step-by-step solution
aligned & S-t 2 + t 2 n₀ =2 f & S+t ( 1 n₀ -1 )=4 f & S=4 f+ (1- 1 n₀ ) t aligned Also aligned & S - t 2 + t 2 n ₀ = f & S =2 f + (1- 1 n ₀ ) t aligned