If your ocular lens magnifies 10 times and your objective le

If your ocular lens magnifies 10 times, and your objective lens magnifies 4 times, what is your total magnification? If your field of view at this magnification is 4.0mm, what is the field of view at 400X total magnification (in microns)? How large is an organism if it covers half the field of view at a total magnification at 1000X (in microns). Show your work and include any formulas you use.

Solution

The light microscope contains two lenses namely the objective lens and the eye piece or ocular lens. The objective lenses are available with different magnification capacity such as 10x, 20x, 40x and 100x.

The size of lens increases with increasing magnification capacity. The Standard ocular lens is, 100X.

The total magnification is calculated by the below formula:

Total magnification = Magnification of ocular lens × Magnification of objective

For example, if the magnification of ocular lens is, 10X and the magnification of objective is 4X, the total magnification is = 10 × 4 = 40X.

The filed of view at 40X magnification is, 4.0mm.

The field of view at 400X magnification is, = 40*4mm/ 400 = 0.4 mm or 400 um.

The field of view at 1000X magnification is = 40*4mm/1000 = 0.16 mm or 160 um.

The organism covers half of the field of view, means its size is, 80 um.