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JEE Main & Advanced Physics Ray Optics Question Bank Microscope and Telescope

  • question_answer
    An astronomical telescope has a magnifying power 10. The focal length of eyepiece is 20 cm. The focal length of objective is                    [MP PMT 2002, 03; Pb. PET 2004]

    A)            2 cm                                         

    B)            200 cm

    C)            \[\frac{1}{2}cm\]                

    D)            \[\frac{1}{200}cm\]

    Correct Answer: B

    Solution :

               \[m=\frac{{{f}_{o}}}{{{f}_{e}}}\Rightarrow 10=\frac{{{f}_{o}}}{20}\Rightarrow {{f}_{o}}=200\ cm\]


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