English, asked by gkaran6349, 11 months ago

What is meant by power of a lens ? Write its SI unit. A student uses a lens of focal

length 40 cm and another of –20 cm. Write the nature and power of each lens.​

Answers

Answered by brainlyuser86
0

Answer:

Power of lens is the reciprocal of focal length ( in meters) of the lens or 100/ f in cm. It's SI unit is Diopter denoted by 'D'.

Explanation:

focal length of 1st lens = 40cm

power = 100/40 = 2.5 D

nature of lens - convex lens

focal length of 2nd lens = - 20 cm

power = 100/20 = 5 D

nature of lens - concave lens

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