Question

The focal length of the convex lens when refractive index of material (n2 = 3/2) kept in water (n1 = 4/3)
is equal to
option:
a) 15 cm
b) 7.5 cm
c) 30 cm
d) 10 cm

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Answer 1

Answer:

15cm is it write please see

Answer 2

I think it’s option d . But anyways cross check it . Sorry..