Question

Two identical convex lenses each of focal length f are kept in contact with each other. The magnitude of the focal length of the combination becomes

Answer 1

Hii

you are welcome in my ans

we know that

power(p)

p= p1 + p2

p = 1/f + 1/f

1/f = 2/f

f =f/2

it become half in combined

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Hope it may helps you