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(a) A small refracting telescope designed for individual use has an objective lens with a diameter of 6.00 cm and a focal length of 1.325 m. What is the f-number of this instrument? (b) The 200-inch-diameter objective mirror of the Mt. Palomar telescope has an f-number of 3.3. Calculate its focal length. (c) The distance between lens and retina for a normal human eye is about 2.50 cm, and the pupil can vary in size from 2.0 mm to 8.0 mm. What is the range of f-numbers for the human eye?
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