How is total magnification calculated in a microscope?

Total magnification in a microscope is calculated by multiplying the magnification power of the ocular lens (eyepiece) by that of the objective lens being used. The ocular lens typically has a fixed magnification, commonly 10x, while the objective lenses can vary in magnification (for example, 4x, 10x, 40x, or 100x).

When you want to determine how much the specimen is enlarged for observation, the combined effect of both lenses is considered, hence the multiplication. For instance, if you're using a 10x ocular lens and a 40x objective lens, the total magnification would be 10 x 40, resulting in 400x total magnification.

This method of calculation is critical for accurately knowing how the specimen will appear under the microscope and enables effective observation and analysis in microbiological studies. Other methods mentioned, such as adding or multiplying incorrect combinations of lenses, do not represent the standard practice for calculating magnification in microscopy.