Question

The objective of a telescope has focal length 120 m and diameter 5 cm. The focal length of the eyepiece is 2 cm. The magnifying power of the telescope for distant object is

• A. 12
• B. 24
• C. 60
• D. 300

Answer 1

The correct option is C 60

Magnifying power of the telescope:
$m=\frac{-f_0}{f_e}(1+\frac{f_e}{D})$
$=\frac{-120}{2}(1+\frac{2}{5})$

$=-60$