Chapter 3, Section 3-1, Data and Calculations, Exercise 1
Page 149
Here is a tip:
NA of a microscope is directly proportional to its resolution.
Explanation
Total magnification is calculated by multiplying the magnifying power of an objective lens and one ocular lens.
Low power setting microscope has a magnification of 100X and is used to examine large-sized specimens and a number of smaller specimens. The microscope is also aligned by using this setting. The numerical aperture of a lens signifies its ability to collect light.
High dry setting is used to obtain a clear, detailed, and sharp image of the specimen.
Oil immersion setting gives finer and detailed images of individual cells such as bacteria or red blood cells.
Scanning lens setting is used in order to get a general overview of the specimen on the slide.
Condenser lens is used to converge light from a divergent beam in order to illuminate the specimen being observed.
Verified Answer
In low power settings, objective lens and ocular lens both have 10X magnifications. Consequently, the total magnification will be 100X. The numerical aperture [NA] of the objective lens is 0.40 and the calibration of the ocular micrometer [μm/OU] is 25.
In a high dry setting, objective lens and ocular lens have 40X and 10X magnification, respectively. Accordingly, the total magnification will be 400X. The numerical aperture of the objective lens is 0.85 and the calibration of the ocular micrometer [μm/OU] is 19.
In an oil immersion setting, objective lens and ocular lens have 100X and 10X magnification, respectively. Consequently, the total magnification will be 1000X. The numerical aperture of the objective lens is 1.30 and the calibration of the ocular micrometer [μm/OU] is 2.5.
In scanning lens settings, objective lens and ocular lens have 4X and 10X magnification, respectively. Accordingly, the total magnification will be 40X. The numerical aperture of the objective lens is 0.4 and the calibration of the ocular micrometer [μm/OU] is 32.