A microscope objective gathers light over a cone of semi-vertex 30° and used visible light of wavelength 5500 Å. Its resolving limit is:
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Question

A microscope objective gathers light over a cone of semi-vertex 30° and used visible light of wavelength 5500 Å. Its resolving limit is:

G1 Physics · Accepted Answer

Microscope resolution d≈0.61λ/(n sinα). Taking NA=sin30°=0.5 and λ=5.5×10⁻⁷ m gives d≈6.7×10⁻⁷ m=6.7×10⁻⁵ cm. Hence option D.