Q130 / 200 · NEET 2002 · Physics
Diameter of human eye lens is $2 \mathrm{~mm}$. What will be the minimum distance between two points to resolve them, which are situated at a distance of $50 \mathrm{~m}$ from eye. The wavelength of light 5000 $Å$.
- A$2.32 \mathrm{~m}$
- B$4.28 \mathrm{~mm}$
- Correct answerC$1.25 \mathrm{~cm}$
- D$12.48 \mathrm{~cm}$
Solution
For the aparture, limit of resolution
$$
\begin{aligned}
& \frac{y}{D} \geq \frac{\lambda}{d} \Rightarrow y \geq \frac{\lambda D}{d} \\
& y \geq \frac{5 \times 10^{-7}}{2 \times 10^{-3}} \times 50 \geq 1.25 \mathrm{~m}
\end{aligned}
$$
Hence, the correct answer is option: 'C'.