Question

An object of height $0.5cm$ is placed laterally in the medium of refractive index $n_1=1.5$ at a distance $100cm$ away form the pole. The radius of curvature of the surface is $20cm$. The height of the image formed after refraction is :

• A. $0.8cm$
• B. $1cm$
• C. $0.25cm$
• D. $1.5cm$

Answer 1

The correct option is A $0.8cm$

$\frac{n_2}{v}-\frac{n_1}{u}=\frac{n_2-n_1}{r}\Rightarrow \frac{1.6}{v}-\frac{1.5}{u}=\frac{1.6-1.5}{20}=\frac{1}{200}$

$\Rightarrow v=-160cm$

Image height$=\frac{v}{u}\times$object height $=-\frac{160}{100}\times 0.5=0.8cm$

Hence $\left(A\right)$ is correct.