A scientist is observing a bacteria through a compound microscope. For better analysis and to improve its resolving power he should. (Select the best option)
Increase the refractive index of the medium between the object and objective lens
Decrease the diameter of the objective lens
Increase the wave length of the light
Decrease the focal length of the eye piece.
Show Solution
The Correct Option isA
Solution and Explanation
The resolving power of a microscope is defined as its ability to distinguish two close points as separate entities. The resolving power can be improved by manipulating several factors. Let's analyze the options:
Increase the refractive index of the medium between the object and objective lens: The resolving power of a microscope depends on the numerical aperture, NA = n \sin(\theta), where n is the refractive index of the medium. Increasing the refractive index increases the numerical aperture, thereby increasing the resolving power. Thus, this option is correct.
Decrease the diameter of the objective lens: Decreasing the diameter of the lens reduces the amount of light gathering ability, which, in turn, reduces the resolving power. Hence, this option is incorrect.
Increase the wavelength of the light: The resolving power is inversely proportional to the wavelength of the light used. Increasing the wavelength would decrease the resolving power. Thus, this option is incorrect.
Decrease the focal length of the eyepiece: The focal length of the eyepiece does not affect the resolving power directly; it primarily affects magnification. Hence, this option does not effectively improve the resolving power and is incorrect.
In conclusion, to improve the resolving power of a compound microscope, the best option is to increase the refractive index of the medium between the object and objective lens.
