Final answer:
The magnification of the objective lens (mo) is inversely related to its focal length (fo), where a shorter focal length leads to a higher magnification. The total magnification of a microscope is the product of the magnifications from the objective lens and the eyepiece.
Step-by-step explanation:
The magnification (mo) of the objective lens in a microscope is inversely related to the focal length (fo) of the lens. The equation for the linear magnification of the objective lens is mobj = 16 cm / fo, where 16 cm is the near point distance for a relaxed eye. This means that as the focal length of the objective lens decreases, the magnification increases. In a compound microscope, the object is placed just outside the focal length of the objective lens to produce an enlarged image, which is then further magnified by the eyepiece acting as a magnifying glass. Therefore, the overall magnification of a microscope, which can be represented as Mnet = mobj x Meye, is dependent on both the linear magnification of the objective and the angular magnification of the eyepiece.