A microscope has an objective of aperture 8 mm and focal length of 5cm .The minimum separation between two objects to be just resolved by the microscope is (wavelength of light used = 5500 Å

Options

A. `2.2 mu"m"`
B. `3.4 mu"m"`
C. `4.2 mu"m"`
D. `3.6 mu"m"`

Answer

C

Explanation

Minimum separation for a microscope , so that images of 2-near by object are just resolved is given by
`d_("min")=(1.22 fgamma)/(D)= (1.22 xx 5 cm xx 5500 Å)/(8 mm)`
`= (1.22 xx 5 xx 10^(-2) xx 5500 xx 10^(-10))/(8 xx 10^(-3))`
`= 41.9 xx 10^(-7) m = 4.19 xx 10^(-6) m = 4.2 mu m`