Question

Normal magnification of a telescope is:
Where $D$ is diameter of object and $d$ is diameter of pupil of the eye

• A. $\frac{D}{d}$
• B. $\frac{d}{D}$
• C. $\frac{D+d}{D}$
• D. $\frac{D-d}{d}$

Answer 1

The correct option is A $\frac{D}{d}$

For viewing clear image through eyepiece, focal length of eyepiece is adjusted so that maximum light passes through it. Therefore, normal magnification of telescope $=\frac{D}{d}$