Answer:
option D
Explanation:
given,
radius of curvature of rain drop = r₁ = 2 mm
radius of curvature of convex lens = r₂ = 2 mm
refractive index of water (n) = 4/3
using lens formula to calculate focal length
[tex]\dfrac{1}{f} = (n-1)(\dfrac{1}{r_1}-\dfrac{1}{r_2})[/tex]
[tex]\dfrac{1}{f} = (\dfrac{4}{3}-1)(\dfrac{1}{2}-\dfrac{1}{-2})[/tex]
[tex]\dfrac{1}{f} = (\dfrac{1}{3})(\dfrac{1}{2}+\dfrac{1}{2})[/tex]
[tex]\dfrac{1}{f} = (\dfrac{1}{3})(1)[/tex]
f = 3 mm
hence, the correct answer is option D
