Question

A planet is observed by astronomical refracting telescope having an objective of focal length 16cm and an eyepiece of focal length 2cm.
A. The distance between the objective and the eyepiece is 16.02 m
B. The angular magnification of the planet is `-800`
C. The image of the planet is inverted
D. The objective is larger then the eyepiece

Answer 1

Correct Answer - A::B::C::D
In case of an astronomical telescope the distance between the objective lens and eyepiece lens
`=f_(0)+f_(e)=16+0.02=16.02m`
The angular magnification`=-(f_(objective))/(f_(eyepeice))=(-16)/(0.02)=-800`
NOTE: The image seen by the astronomical telescope is inverted. Also the objective lens is larger than eye piece lens.