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_(o))`
`implies(I)/(50)=(200xx10^(-2))/(2xx10^(3))impliesI=5xx10^(-2)m=5cm.`