A college observatory wishes to set up an astronomical telescope that must satisfy…
PHYSICS · Subjective · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments
Problem
A college observatory wishes to set up an astronomical telescope that must satisfy the following requirements:
• Angular magnification in normal adjustment: 60
• Maximum permissible length of the telescope tube: 1.6 m
(a) Determine suitable focal lengths for the objective and the eyepiece that meet both requirements, assuming thin lenses are used.
(b) If the observatory intends to view extremely faint galaxies and therefore needs an objective aperture of 4 m, which type of telescope—refracting or reflecting—should be selected? Justify your choice with reference to (i) optical aberrations and (ii) mechanical considerations.