Question

Draw a ray diagram to show formation of an image by a compound microscope or an astronomical telescope

Answer 1

Astronomical Telescope: Magnifying power of astronomical telescope in normal adjustment is defined as the ratio of the angle subtended at the eye by the final image to the angle subtended at the eye, by the object directly, when the final image and the object both lie at infinite distance from the eye.



Magnifying power, m = β/α   (1) 

As angles α and β are small, therefore, α ≈ tanα and β ≈ tanβ.

 

where C1B' = f0 focal length of objective lens, 

C2B' = - fe  focal length of eye lens. 

Negative sign of m indicates that final image is inverted. 

The diameter of objective is kept large to increase (i) intensity of image, (ii) resolving power of telescope.

Answer 2

please refer the attachments

hope this is useful to you.

1) compound microscope

2) astronomical telescope