JEE Main20252 Apr 2025Evening ShiftPhysicsRay OpticsActual
A bi-convex lens has radius of curvature of both the surfaces same as 1 / 6 ~cm . If this lens is required to be replaced by another convex lens having different radii of curvatures on both sides (R₁ R₂ ) , without any change in lens power then possible combination of R₁ and R₂ is :
Options
- A1 3 ~cm and 1 3 ~cm
- B1 5 ~cm and 1 7 ~cm
- C1 3 ~cm and 1 7 ~cm
- D1 6 ~cm and 1 9 ~cm
Correct answer
B. 1 5 ~cm and 1 7 ~cm
Step-by-step solution
This will happen when aligned & 1 f ₁ = 1 f ₂ & ( -1) ( 1 R ₁ - 1 - R ₂ )=( -1) ( 2 R ) & 1 R ₁ + 1 R ₂ = 2 R aligned