Adisadvantage of the astronomical telescope for

Chapter , Problem 87

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Adisadvantage of the astronomical telescope for terrestrial use (for example, at a football game) is that the image is inverted. A Galilean telescope uses a converging lens as its objective, but a diverging lens as its eyepiece. The image formed by the objective is at the second focal point of the eyepiece (the focal point on the refractedlight side of the eyepiece), so that the final image is virtual, upright, and at infinity. (a) Show that the magnifying power is given by where is the focal length of the objective and is that of the eyepiece (which is negative). (b) Draw a ray diagram to show that the final image is indeed virtual, upright, and at infinity.