Calculate the limit of resolution for the oil lens of your microscope. assume an average wavelength of 500 nm

The resolution of a microscope is the distance with the shortest measurement between two different points given a specimen  with the premise that it can still be seen clearly or distinguished by the one looking through the microscope. It can be calculate from the ratio of the wavelength of the light and twice the numerical aperture or the refractive index of the lens. Most of the microscopes have a numerical aperture ranging from 1.2 to 1.4. Resolution and the numerical aperture are indirectly proportional so that as the aperture increases the resolution would decrease. We calculate as follows:

Resolution = wavelength / ((2) (numerical aperture))
Resolution = 500 nm / (2 ) ( 1.25) = 200 nm  = 0.2 um