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\psfig{file=problems/prob_12_8.eps,height=2.5in}
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The arrangement of lenses that makes up a compound microscope is pictured above. The focal lengths of the objective and eyepiece lenses are $f_o = f_e = f = 1$ cm. The tube length is $L = 19$ cm.

a) Find $s$ (the object distance from the objective lens) such that the final image viewed by the eye is in focus (at infinity, as imaged by the eyepiece).

b) Draw the ray diagram from which you can find the overall magnification (try to use a straight edge to do this).

c) From this diagram and your knowledge of the separate purposes of the two lenses, find the overall magnification. Explain each part (that is, what are the separate roles of the objective and eyepiece).


Robert G. Brown 2003-02-09