Question

Write for the formula for resolution of microscope and explain the symbols used.

Answer 1

Hint: Using the wavelength of light and the refractive index of the medium. Resolving power is the ability to separate the images of two nearby points objects so that they can be distinctly seen.

 Complete step-by-step solution:
The resolving power of a microscope is the reciprocal of the smallest distance between two point objects at which they can be just when seen through the microscope.
Formula for limit of resolution of microscope is given by: $$d={\displaystyle \frac{\lambda }{2\mu \sin \theta }}$$
On reciprocal of above equation we get the formula for resolving power of microscope which is given by: ${\displaystyle \frac{1}{d}}={\displaystyle \frac{2\mu \sin \theta }{\lambda }}$
Here, $\lambda =$ the wavelength of the light speed
$$\theta =$$half angle of the cone of light from each point object or the angle subtended by each point object on the radius of the objective.
$$\mu =$$the refractive index of the medium between the point object and the objective of the microscope.
Factor $$\mu \sin \theta$$ is called the numerical aperture.

Note:- Remember resolving power of microscope is the reciprocal of the limit of the resolution. Smaller the limit of resolution, d, the greater will be the resolving power.