Q 12-09-213JEE MainJEE Main 2019 (12 Apr, Shift 1)Easy
The value of numerical aperture of the objective lens of a microscope is $1.25$. If light of wavelength $5000$ Å is used, the minimum separation between two points, to be seen as distinct, will be:
Answer: (B) $0.24\ \mu$m
Limit of resolution of a microscope:
$$d_{\min} = \frac{1.22\lambda}{2\,\text{NA}} = \frac{1.22\times0.5\ \mu\text{m}}{2\times1.25} \approx 0.24\ \mu\text{m}$$
Solution by Sreeraj P, M.Sc Physics