Two thin lenses of power +5D and –2.5D are in contact. What is the focal length of the combination?

Two thin lenses of power +5D and –2.5D are in contact. What is the focal length of the combination?

Monjur Alahi

12 views

2025-01-04 04:42

1 Answers

Salim Ahmed Kawsar

Net power, P = P₁ + P₂ = + 5 - 2.5 = +2.5D

∴ Focal length, F = 1/P = 1/2.5m = 0.4m =40cm

12 views Answered 2023-02-05 15:29

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