Question

The image for converging beam after refraction through the curved surface ( in the given figure) is formed at

• A. $X=40cm$
• B. $X=\frac{40}{3}cm$
• C. $X=-\frac{40}{3}cm$
• D. $X=\frac{180}{7}cm$

Answer 1

The correct option is A $X=40cm$

$\begin{array}{c}\text{Here}u=+30\\ R=+20\\ \frac{{\mu }_1}{u}-\frac{{\mu }_2}{v}=\frac{{\mu }_1-{\mu }_2}{R}\\ \frac{3}{2}\\ \frac{1}{30}-\frac{1}{v}=\frac{\frac{3}{2}-1}{20}\\ \frac{1}{v}=\frac{1}{40}\\ v=40cm\end{array}$

$\text{So option}A\text{is correct}$