Find the equivalent power of the thin-lens combination shown in the original figure. The figure indices are μ₁=4/3, μ₂=3/2 and μ₃=4/3, and the surface radii are R₁ and R₂.
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Question

Find the equivalent power of the thin-lens combination shown in the original figure. The figure indices are μ₁=4/3, μ₂=3/2 and μ₃=4/3, and the surface radii are R₁ and R₂.

G1 Physics · Accepted Answer

Net power is the sum of the powers of the re \fracting \fracting \fracting surfaces: P = (μ₁-μ₂)/R₁ + (μ₃-μ₂)/R₂. Using μ₁ = μ₃ = 4/3, μ₂ = 3/2, P = (4/3-3/2)(1/R₁+1/R₂) = -(1/6)(1/R₁+1/R₂) = -(R₁+R₂)/(6R₁R₂).