Question

A large reflecting telescope has an objective mirror with a 10.0m radius of curvature. What angular magnification does it produce when a 3.00m focal length eyepiece is used?

Short answer

The angular magnification is found to be - 1.667.

Step-by-step solution

Concept Introduction

The ratio of size of image to the size of object is known as magnification.

Calculating the magnification for a thin lens

The radius of curvature is equal to R = 2f, as we know.

The angular magnification is supplied by, as we said before in the idea session.

$$\begin{gathered} M=\frac{{\theta }^{\text{'}}}{\theta }=-\frac{f_{\circ }}{f_e} \\ =-\frac{{\displaystyle \frac{R}{2}}}{f_e} \\ =-\frac{10m}{2} \\ =-1.667 \end{gathered}$$

Therefore, M = - 1.667 is the angular magnification.