question_answer

Explain with reason, how the resolving power of a compound microscope will change when (i) frequency of the incident light on the objective lens is increased, (ii) focal length of the objective lens is increased, and (iii) aperture of the objective lens is increased.                                        

Answer:

                R.P. of a compound microscope \[=\frac{2\mu \sin \theta }{\lambda }=\frac{2\mu \sin \theta \times v}{c}\] (i) When the frequency v of the incident light increases, the resolving power increases (R.P\[\propto v\]). (ii) Resolving power does not change with change in focal length of objective lens. (iii) When the aperture of the objective lens increases, the semi vertical angle \[\theta \] increases and hence the resolving power of the microscope increases.