Question

Formation of real image using a biconvex lens is shown below. If the whole set up is immersed in water without disturbing the object and the screen position, what will one observe on the screen?

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

Answer 1

The correct option is B Image disappears

we know that: $\frac{1}{f}=(\mu -1)(\frac{1}{R_1}-\frac{1}{R_2})$

• Focal length of lens will change if the whole set up is immersed in water without disturbing the object and the screen position.
• From lens formula if focal length will change then image location will change hence image disappears from the screen.

Similar case as myopia and hypermetropia.

Hence correct option is $A$.