Two thin lenses having R₁, R₂ as the radii of curved surfaces are kept coaxially together. Their power is proportional to

Step-by-step solution

Power of coaxial thin lenses The power of a thin lens follows the lens maker's formula P = ( - 1) ( 1 R₁ - 1 R₂ ) , where is the refractive index and R₁ , R₂ are the radii of curvature with proper sign convention. For plano-convex lenses with curved surfaces of radii R₁ and R₂ respectively, the flat surfaces contribute 1/ = 0 to the curvature terms. The individual powers become P₁ = - 1 R₁ and P₂ = - 1 R₂ . When placed coaxially in contact, the combined power sums to P_ total = P₁ + P₂ = ( - 1) ( 1 R₁ + 1 R₂ ) . Th