question_answer

How will the magnifying power of a refracting type astronomical telescope be affected on increasing for its eyepiece (i) the focal length and (ii) the aperture? Justify your answer.                

Answer:

                (i) As\[m=\frac{{{f}_{0}}}{{{f}_{e}}},\], so that magnifying decreases when focal length of eye-piece increases. (ii) Magnifying power is not affected by the increase in aperture of the eyepiece.