Find the focal length of the lens whose power is – 2.0 D. What is the type of lens?

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Chapter 9 NCERT Class 10 Science SOLUTIONS

16. Find the focal length of the lens whose power is – 2.0 D. What is the type of lens?

Question:

Find the focal length of the lens whose power is – 2.0 D. What is the type of lens?

Answer:

Here P = –2.0 D

Power of lens P = 100/f (in cm)

f = 100/P

f = -100/2

f = 50 cm

f = negative. Thus, it is a concave lens.

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