Question

Give scientific reason for the following.
(a) The focal length of the eyepiece of a compound microscope is larger.
(b) A telescope of a binocular has two total internal reflecting prisms.

Answer 1

Hint:Focal length is the distance between the centre of lens and the focal point (Point where the intersection of two points takes place) and compound microscopes have multiple lenses for enhanced scope so smaller things could be seen much clearer. A telescope of a binocular mostly consists of prism which reflect at \[{{90}^{\circ }}\text{ or }{{180}^{\circ }}\](total internal reflection).

Complete answer:
A compound microscope is built with multiple lenses which leads to a multiplied scope which helps to see much closer and these microscopes can be adjusted for different variation lengths due to this phenomenon.

And due to this very reason, the lower lens is adjusted to the low focal length with the point of observation for better results which leads to farer distance to eye piece which is why compound microscopes have larger focal lengths of the eyepiece.

A telescope of a binocular is built with right angled prisms which can reflect at \[{{90}^{\circ }}\text{ or }{{180}^{\circ }}\] mostly this ${{90}^{\circ }}$are used for bending as seen in submarines. ${{180}^{\circ \pm }}$ angle is used for total internal reflection and as binoculars have two barrels of telescope it consists of two right angled prisms.This is why a telescope of binoculars has two total internal reflecting prisms.

Note:A standard compound microscope is built with four lenses and for certain requirements more lenses are used or fewer sometimes. Binoculars are low magnified for watching closer compared to proper telescopes which can actually see really far.