Physics - Geometrical Optics Question with Solution | TestHub

$\text{Let}[\frac{1}{{\text{R}}_1}-\frac{1}{{\text{R}}_2}]=\text{x}$

$\therefore \frac{1}{\text{f}}=[\frac{\frac{3}{2}}{1}-1][\frac{1}{{\text{R}}_1}-\frac{1}{{\text{R}}_2}]\Rightarrow \text{f}=\frac{2}{\text{x}}$

When in liquid 1

$\frac{1}{{\text{f}}_1}=[\frac{\frac{3}{2}}{\frac{4}{3}}-1][\frac{1}{{\text{R}}_1}-\frac{1}{{\text{R}}_2}]\Rightarrow {\text{f}}_1=\frac{8}{\text{x}}$

When in liquid 2

$\frac{1}{{\text{f}}_2}=[\frac{\frac{3}{2}}{\frac{5}{3}}-1][\frac{1}{{\text{R}}_1}-\frac{1}{{\text{R}}_2}]\Rightarrow {\text{f}}_2=\frac{-\text{10}}{\text{x}}$