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 e R₂), without any change in lens power then possible combination of R₁ and R₂ is

Question

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 
e R₂), without any change in lens power then possible combination of R₁ and R₂ is

Accepted Answer

(3) 1/5 cm and 1/7 cm. Power depends on 1/(R₁)+1/(R₂) for the same material. Original: 6+6 = 12 cm⁻¹. Option (c): 5+7 = 12 cm⁻¹ with unequal radii. → option 3

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 e R₂), without any change in lens power then possible combination of R₁ and R₂ is

Step-by-step solution

Why the other options are wrong