Question

A gaint refracting telescope at an observatory has an objective lens of focal length of focal length 15 m. If an eye piece of focal length 1.0 cm is used , what is the angular magnification of the telescope ?

• A. 1000
• B. 1500
• C. 2000
• D. 3000

Answer 1

Answer: (B)

1500

Answer 2

: Here, $f_{o} = 15m = 15 \times 10^{2}cm,f_{e} = 1.0cm$

$\therefore$ magnification, $m = \frac{f_{o}}{f_{e}} = \frac{15 \times 10^{2}}{1}$

M = 1500