PASCO OS-8459 Beginning Optics System - Manual (Page 30)

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B e g i n n i n g O p t i c s S y s t e m E x p e r i m e n t 1 0 : F o c a l L e n g t h a n d M a g n i f i c a t i o n o f a T h i n L e n s
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2. Calculate the absolute value of M (for each of the two lens positions) using your
measurements of the image size and object size. Record the results in Table 10.3.
(eq. 10.3)
3. Calculate the percent differences between the absolute values of M found using
the two methods. Record the results in Table 10.3.
QUESTIONS
1. Is the image formed by the lens upright or inverted?
2. Is the image real or virtual? How do you know?
3. Explain why, for a given screen-to-object distance, there are two lens positions
where a clear image forms.
4. By looking at the image, how can you tell that the magnification is negative?
5. You made three separate determinations of f (by measuring it directly with a dis-
tant object, from the x-intercept of your graph, and from the y-intercept). Where
these three values equal? If they were not, what might account for the variation?
M
image size
object size
------------------------- =
Table 10.3: Magnification
Point 1 Point 2
calculated from image and object distances
calculated from image and object sizes
% difference
M
M