A telescope has an objective lens of focal length `200cm` and an eye piece with focal length `2cm`. If this telescope is used to see a 50 meter tall building at a distance of `2km,` what is the height of the image of the building formed by the objective lens?

Options

A. 5 cm
B. 10 cm
C. 1 cm
D. 2 cm

Answer

A

Explanation

Magnification of objective lens
m `= (I)/(O) = (v_(o))/(u_(o)) = (f_(o))/(u_(0)) rArr (I)/(50) = (200 xx 10^(-2))/(2 xx 10^(3))`
I = 5 cm.