A Cassegrain telescope uses two mirrors as shown in Fig. 9.33. Such a telescope is built with the mirrors 20mm apart. If the radius of curvature of the large mirror is 220mm and the small mirror is 140mm, where will the final image of an object at infinity be?

An object is placed in front of convex mirror 20 cm radius of curvature.Its image is forced 8 cm behind the mirror.Find the distance of the object from the miror.

A reflecting type telescope has a large spherical mirror for its objective with radus of curvature equal to 80 cm.What is the magnifying power of telescope,if eyepiece used has a focal length of 1.6 cm.

An object 2 cm high is placed at a distance of 5 cm from a concave mirror,whose radius of curvature is 20 cm.Find the position of the image.

A convex lens of focal lenght 20 cm is placed coaxially wih a convex mirror of radius of curvature 20 cm.the two are kept at 15 cm apart.A point object lies 60 cm in front of the convex lens.Draw a ray diagram to show the formation of the image by the combination.Determine the nature and position of the image formed.

An object 5.0 cm of length is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position of the image,its nature and size.

An object is placed 21 cm in front of a concave mirror of radius of curvature 10 cm.A glass slab of thickness 3 cm and refractive index 1.5 is then placed close to the irror in the space between the object and mirror as shown in Fig.2.62.Find the position of the final image formed.You may take the distacne of the near surface of the slab from the mirror to be 1 cm. .

An equiconvex lens with radii of curvature of magnitude R each,is put over a liquid layer poured on top of a plane mirror.A small needle ,with its tip on the principal axis of the lens,is moved along the axis until its inverted real image coincides with the needle itself.The distance of the needle from the lens is measured to be a as shown in Fig.2.53. On removing the liquid layer and repeating the ezperiment,the distance is found to be b as shown in Fig.254 .Gien that tow values of distances meeawured reepresent the focal length values in the two cases, obtain a formula for the refractive index of the liquid. .