Chapter 18.2, Problem 27SSC

To determine

To explain: The reasonfor not observing the chromatic aberration effect if the object is seen through a microscope.

Answer to Problem 27SSC

The chromatic aberration effect is not seen even if the object is seen through a microscope because achromatic lens are used that minimize the effect of chromatic aberration.

Explanation of Solution

Introduction:

The focal length of a lens is governed by the refractive index of the material from which the lens is made up of. For the increase in wavelength, most of the materials show decrease in their refractive index. Hence there will be variation in the refractive index of the lens due to the wavelength of light. Because of this variation in refractive index, it is not possible for a lens to focus light rays of all the wavelengths to a common focal point. This leads to a deception in an image of the object and is termed as chromatic aberration.

If a lens is used in an optical instruments, there will be distortion in the image due to the chromatic aberration. In order to minimize this chromatic aberration, instead of a single lens, a combination of lenses,that are made from different materials, are used in high quality optical instruments. This combination of lenses is known as achromatic lens. In microscope, achromatic lenses are used and hence no chromatic aberration effect is observed.