• # question_answer 39) The astronomical microscope consists of objective and eyepiece. The focal length of the objective is: A)  five times shorter than of eyepieceB)  shorter than that of eyepieceC)  greater than that of eyepieceD)  equal to that of eyepiece

The magnifying power of an astronomical telescope is given by $=\frac{{{f}_{o}}}{{{f}_{e}}}\,\left( 1+\frac{{{f}_{e}}}{D} \right)$ Therefore, in order to increase the magnifying power of a telescope, the focal length ${{f}_{o}}$ of the objective lens should be large.