CUET Preparation Today
The focal length of a thin lens in vacuum is $f$. If the material of the lens has refractive index $\frac{3}{2}$, its focal length when immersed in water of refractive index $\frac{4}{3}$ would be: |
$2f$ $f$ $4f$ $\frac{4f}{3}$ |
$4f$ |
The correct answer is Option (3) → $4f$ |
