Question

Formation of a real image using a biconvex lens is shown below:


If the whole set up immersed in water without disturbing the object and the screen positions, what will one observe on the screen?

• A. Magnified image
• B. No change
• C. Image disappears
• D. Erect real image

Answer 1

The correct option is C Image disappears

According to lens maker's formula,

$\frac{1}{f}=({\mu }_{rel}-1)(\frac{1}{R_1}-\frac{1}{R_2})$

Focal length of a lens will change due to change in refractive index ${\mu }_{rel}$. So, the image will be formed at the new position. Hence, image disappears

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