Physics

Problem

An observatory plans to build a ground-based telescope with an aperture of

4\,\text{m}

that must be free from chromatic aberration. Which of the following designs is most suitable? a) Refracting telescope with a

4\,\text{m}

diameter achromatic doublet objective lens b) Newtonian reflecting telescope with a

4\,\text{m}

diameter parabolic primary mirror c) Newtonian reflecting telescope with a

4\,\text{m}

diameter spherical primary mirror d) Galilean telescope with a

4\,\text{m}

diameter convex objective lens and concave eyepiece