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69. ssm A converging lens (f = 12.0 cm) is located 30.0
cm to the left of a diverging lens (f = - 6.00 cm). A postage
stamp is placed 36.0 cm to the left of the
converging lens. (a) Locate the final image of the stamp
relative to the diverging lens. (b) Find the overall
magnification. (c) Is the final image real or virtual?
With respect to the original object, is the final image (d) upright or inverted, and
is it (e) larger or smaller? |
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So with multiple lenses, you find the image
of the first lens and make that the object for the second lens and then you
can find the final image. So first find the image of the left lens. |
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The object distance for the
second lens is found from |
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Now find the second image
using this object distance |
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The minus sign implies the
second image is virtual and located 4.00 cm to the left of the diverging
lens! |
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Overall magnification is found
from |
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As mentioned above, the final
image is virtual, it is inverted, and smaller. We know this from the overall magnification
being <1 makes it smaller. The
converging lens creates an inverted image, but the diverging lens does not
invert, so the final image is inverted with respect
to the original object. |
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