question_answer

The value of numerical aperature of the objective lens of a microscope is 1.25. If light of wavelength \[5000\text{ }{\AA}\] is used, the minimum separation between two points, to be seen as distinct, will be : [JEE Main Held on 12-4-2019 Morning]

A) \[0.24\mu m\]

B) \[0.48\mu m\]

C) \[0.12\mu m\]

D) \[0.38\mu m\]

Correct Answer: A

Solution :

[a] Numerical aperature of the microscope is given as

Where d = minimum sparation between two points to be seen as distinct