Microscope Magnification Quiz

Observe the powers found on your microscope’s lenses and fill in the chart below. Magnifications Available on BJA Microscopes When using the: Ocular: _______ X Objective: _______ X Total Magnification: _______ X Lowest-power objective: _______ X _______ X _______ X Low-power objective: _______ X _______ X _______ X High-power objective: _______ X _______ X _______ X

What does "20X" mean when referring to the power of a microscope lens?

How do you calculate the total magnification of a compound microscope?

Why should a magnification of 40X (4X objective) not be used for drawings in Biology?

What should you do if you run into difficulties while observing specimens?

List the steps to set up the microscope as described in the worksheet.

Note some of the effects of using the light microscope and answer these questions. If you move the slide to the right, how does the position of the material change in your field of view?

Turn the fine adjustment knob slowly to move the stage up and down slightly. Describe what happens to the image.

Why is it essential that the specimen be in the center of the microscope field when changing from low to high power?

On high power you cannot get all of a desmid (especially larger ones) in focus at the same time. As you adjust the fine adjustment knob parts come into focus, but some parts go out of focus. Why?