Name the telescope which having concave lens as eyepiece.

Name the lens LL'.

Ranbir claims to have obtained an image twice the size of the object with a concave lens. Is he correct? Give a reason for your answer.

If f_o and f_e are the focal lengths of the objective lens and eye-piece lens respectively for a telescope, the length of telescope in normal adjustment is

An astronomical telescope is adjusted to form the final image at infinity. The separation between the lenses is 80 cm. The angular magnification is 15. Calculate the focal lengths of the objective lens and the eyepiece.

A convex lens of focal length 1 meter and a concave lens fo focal length 0.25 meter and kept 0.75 meter apart. A parallel beam of light first passes through the ocnvex lens, then through the concave lens and comes to a focus 0.5m away from the concave lens.

We combined a convex lens of focal length f_(1) and concave lens of focal lengths f_(2) and their combined focal length was F . The combination of these lenses will behave like a concave lens, if

A reflecting type telescope has a large concave spherical mirror of radius of curvature 80 cm as objective. What is the magnifying power of telescope if eye piece used has a focal length of 1.6 cm ?

Your are given following three lense. Which two lenses will you use as an eyepiece and as an objective to construct as astronomical telescope ?

Find the maximum magnifying power of a compound microscope having a 25 diopter lens as the objective, a 5 diopter lens as the eyepiece and the separation 30 cm between the two lenses. The least distance for clear vision is 25 cm.

A small telescope has an objective lens of focal length 140 cm and an eyepiece of focal length 5.0 cm. what is the magnifying power of the telescope for viewing distant objects when (a) the telescope is in normal adjustment (i.e, when the final image is at infinity ), (b) The final image is formed at the least distance of distinct vision (25 cm )