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प्रश्न
Draw a ray diagram of a refracting astronomical telescope when final image is formed at infinity. Also write the expression for its angular magnification (magnifying power).
उत्तर
Magnifying power
M = `- "f"_"o"/"f"_"e" (1 + "f"_"e"/"D")`, when image is formed at D
M = `- "f"_"o"/"f"_"e"`, when image is formed at infinity.
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