Passage IV
The total magnification provided by a compound light microscope is determined by multiplying the power (magnification) of the ocular lens (eyepiece) by the power of the objective lens. The area seen when looking through a microscope is called the field of view (FOV). The diameter of the FOV varies with total magnification. Table 1 gives the power of, and the FOV diameter associated with, 4 different objective lenses on a microscope (Microscope M) with an ocular lens power of 10x. Table 2 lists 4 types of microscopic organisms found in pond water and gives their size ranges and their distinguishing characteristics.
19. Suppose a student wants to use Microscope M to view an organism. Which objective lens should the student first use to locate the organism, and why?
Your Answer is
Correct Answer is A
Explanation
General knowledge questions.
When you don’t know the size of the microorganisms to be observed, you should first use a large FOV to observe the whole; if you can’t see clearly, then change to a smaller FOV