Difference between revisions of "Problem Set 1"
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− | In lab, you are going to build a microscope. As discussed in lecture, a single lens can act as a magnifier. You have certainly used a magnifying glass to look at something small. But microscopes that achieve very high magnifications use multiple lenses in series to make an image. This is clearly a much more expansive design. Why not use a single lens as a high-magnification microscope | + | In lab, you are going to build a microscope. As discussed in lecture, a single lens can act as a magnifier. You have certainly used a magnifying glass to look at something small. But microscopes that achieve very high magnifications use multiple lenses in series to make an image. This is clearly a much more expansive design. Why not use a single lens as a high-magnification microscope? |
* List three potential problems with this idea. Explain how the problems arise, using the information you learned about the behavior of light from lecture. | * List three potential problems with this idea. Explain how the problems arise, using the information you learned about the behavior of light from lecture. |
Revision as of 16:28, 3 February 2009
Contents
Question 1
For this question, you will need to stop by the lab and make a few measurements of lenses. The whole thing should take about twenty minutes.
- Measure the focal lengths of the lenses marked A, B, and C
- Turn on the halogen lamp.
- Move the screen to produce a focused image.
- Measure the distance d1 from the imaging target to the 75mm lens, the distance d2 from the lens to the screen, and the height H of a feature on the image.
- Repeat this measurement for several values of d1
Part a
- What is your estimate of the focal lengths of lenses A, B, and C?
Part b
- What is the relationship between d1, d2, and H? Make a plot of your measurements that shows this relationship.
Question 2
In lab, you are going to build a microscope. As discussed in lecture, a single lens can act as a magnifier. You have certainly used a magnifying glass to look at something small. But microscopes that achieve very high magnifications use multiple lenses in series to make an image. This is clearly a much more expansive design. Why not use a single lens as a high-magnification microscope?
- List three potential problems with this idea. Explain how the problems arise, using the information you learned about the behavior of light from lecture.
HINT: Think about the underlying assumptions used in geometric optics. Under what circumstances in a real microscope design is each assumption violated? How do these violations impact the final image? If you are stuck, go back to the lecture slides and take a close, logical look at each assumption. Where does each assumption break down?
BONUS CREDIT: For each problem you identify with using a single lens microscope, explain in a sentence or two and a brief sketch how multiple lenses might ameliorate the problem.