Which mirror is used inmagnifying glass

A diverging lens with \(f=-30.0 \mathrm{~cm}\) is placed \(15.0 \mathrm{~cm}\) behind a converging lens with \(f=20.0 \mathrm{~cm}\). Where will an object at infinity in front of the converging lens be focused?

Whichlensis used inmagnifying glassand where should the object be placed

Two identical thin convex lenses, each of focal length \(f\), are separated by a distance \(d=2.5 f\). An object is placed in front of the first lens at a distance \(d_{\mathrm{a}, 1}=2 f .\) a) Calculate the position of the final image of an object through the system of lenses. b) Calculate the total transverse magnification of the system. c) Draw the ray diagram for this system and show the final image. d) Describe the final image (real or virtual, erect or inverted, larger or smaller) in relation to the initial object.

What type of lensis used to make amagnifying glassconverging or diverging

A refracting telescope has the objective lens of focal length \(10.0 \mathrm{~m}\). Assume it is used with an eyepiece of focal length \(2.00 \mathrm{~cm}\). What is the magnification of this telescope?

When sharing binoculars with a friend, you notice that you have to readjust the focus when he has been using it (he wears glasses, but removes them to use the binoculars). Why?