An astronomical telescope is to be designed to have a magnifying power of 50 in normal

adjustment. If the length of the tube is 102 cm, find the powers of the objective and the eyepiece.


Given data -


Magnifying power of the astronomical telescope, m = 50


Length of the tube, L = 102 cm


Let f0 and fe, be the focal length of objective and eye piece


Then using the formula for magnification, m



Substituting the values-




Also


Substituting (2) in (1)








And, substituting the value in (1)




Hence, the power, which is reciprocal of focal length becomes-


For objective lens -



And,


For eye piece lens



1