Question

Focal length of a convex lene is 20cm. it's power is:​

Answer 1

Answer:

Biosphere reserves are 'learning places for sustainable development'. They are sites for testing interdisciplinary approaches to understanding and managing changes and interactions between social and ecological systems, including conflict prevention and management of biodiversity

Answer 2

Answer:

P = 1 / f = 1 / 20 = 100 / 20 = 5 Diopter

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