Physics, asked by ajitsingh7185, 1 year ago

An eye specialist prescribe spectacles having combination of convex lens of focal length 40 cm in contact with a concave lens of focal length 25 cm coaxially the power

Answers

Answered by Deveshattri
3
f of concave lens = -40cm = -0.4m
power = 1/-0.4 = -2.5 D

f of convex lens = 25 cm = 0.25m
power = 1/0.25 = +4 D
total power = -2.5 + 4
=1.5 D
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