Name: _____________________	Lab: Wed12-3/Thu12-3/Thu3-6
SSN:   _____________________	Date: _____________________

Physics 135bL
Quiz #8
(4pts. each)


1. T/F: A converging lens has a negative focal length.
Answer:
False. A converging lens has positive focal length. A diverging lens produces a virtual image (usually upright); converging lens usually produces inverted, real image.


2. Suppose a positive lens has a focal length f = 20cm and an object is placed at a distance of d_o = 50cm from this lens. Please calculate the image distance d_i for this situation.
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Answer:
33.33 cm


3. For the above scenario, is the image virtual or real? Suppose the height of the object is h_o = 10cm and the height of the image is h_i = -16.7cm. Is the image inverted or upright?
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Answer:
Converging lens so real; negative mag. so inverted


4. Draw a diagram of the eye. Please be sure to include at least the retina, iris, cornea, and lens.


See http://www.science.mcmaster.ca/Psychology/psych2e03/lecture2/eye.jpg


5. Suppose Calvin's dad suffers from myopia. What can you conclude about his spectacles?
Answer:
B -- They have diverging lenses.

1. They have converging lenses.
2. They have diverging lenses.
3. They have cylindrical lenses.
4. They are held together with Geek^® tape.