Question

Resolution power of a compound microscope is
A.100μm
B.10μm
C.1μm
D.0.25μm

Answer 1

A compound microscope is designed with a compound lens system. In a compound microscope, the image is relayed by two lenses, i.e., objective and the eyepiece or ocular.

Complete answer:
A compound microscope is an optical instrument. It is used for obtaining magnified images of small objects. It consists of an objective lens with a very short focal length and an eyepiece with a longer focal length, both lenses mounted in the same tube. The resolving power of a microscope is defined as the ability to distinguish between two closely spaced structures or images. Resolving power denotes the smallest detail that a microscope can resolve when imaging a specimen.

A compound microscope uses two lenses at once to magnify the image of a specimen. The ocular lens is found in the eyepiece while the objective lens is found in the revolving nosepiece. The resolving power is the capacity of an instrument to resolve two points that are close together. The resolving power of a compound microscope is 0.25μm. Thus, the correct option is D) 0.25μm.

Additional information: The various advantages of compound microscope are,
i) It is very simple and easy to use.
ii) It has its own light source and thus an external light source is not required.
iii) As there are multiple lenses, a great amount of details of the sample can be obtained.

Hence the correct answer is option ‘D’.

Note: It should be noted that the compound microscope uses two sets of lenses. It is used to obtain higher magnification than a stereo microscope. A compound microscope provides a two-dimensional image, whereas a stereo microscope provides a three-dimensional image.