Question

An equiconvex lens made of glass of refractive index $\frac{3}{2}$ has focal length f in air. It is completely immersed in water of refractive index $\frac{4}{3}$. The percentage change in the focal length is

• A. 300% decrease
• B. 400% decrease
• C. 300% increase
• D. 400% increase

Answer 1

Answer: (C)

300% increase

Answer 2

The correct answer is (C) : 300% increase.