question_answer

A telescope has an objective lens of focal length 150 cm and an eyepiece of focal length 5 cm. If a 50 m tall tower at a distance of 1 km is observed through this telescope in normal setting, the angle formed by the image of the tower is \[\theta \], then\[\theta \], is close to:               [JEE ONLINE 10-04-2015]

A) \[{{60}^{o}}\]         

B) \[{{15}^{o}}\]

C) \[{{1}^{o}}\]

D) \[{{30}^{o}}\]

Correct Answer: A

Solution :

[a] Angular magnification on

so,