1
A student wishes to study the cell structure under a light microscope having 10X eyepiece and 45X objective. He should illuminate the object by which one of the following colours of light so as to get the best possible resolution ?
- Yellow
- Red
- Blue
- Green
Answer
(3) Blue
Solution
The limit of resolution of a microscope is d = 0.61 NA.
⇒ The smaller the wavelength , the smaller is d, i.e. the better is the resolution.
⇒ Among the given colours, blue light has the shortest wavelength (red > yellow > green > blue).
∴ The object should be illuminated with blue light.
Answer: (3)
AIPMT 2005