Question

A thin convex lens made from crown glass $(\mu =\frac{3}{2})$ has focal length f. When it is measured in two different liquids having refractive indices $\frac{4}{3}and\frac{5}{3}$, it has the focal lengths $f_{1}and{f}_2$ respectively. The correct relation between the focal lengths is:

• A. $f_2>fand{f}_1$ becomes negative
• B. Both $f_{1}and{f}_2$ become negative
• C. $f_1=f_2<f$
• D. $f_1>fand{f}_2$ becomes negative

Answer 1

The correct option is D $f_1>fand{f}_2$ becomes negative

use lens maker formula for every case and find the relation f1=4f and f2= -5f
Watch the next video for the solution.