A equiconvex lens of focal length 30 cm is divided into two equal halves in thickness.find the focal lnegth of eah half.

Define focal length of a lens

A convex lens of focal lenth 30 cm and a concave lens of focal length 60 cm are placed in contact.Find the power of the combination.

Two lenses convex lens of focal length 30 cm in contact with a concave lens of focal length 20 cm, if they are placed 8.0 cm apart with their principal axes coincident. An object 1.5 cm in size is placed on the side of the convex lens. The distance between the object and the convex lens is 40 cm. Determine the magnification produced by the two-lens system, and the size of the image.

A concave lens is kept in contact with a convex lens of focal length 20 cm.The combbination works as a convex lens of focal length 50 cm.Find the power of the concave lens.

A biconvex lens of focal length 15 cm is in front of a plane mirror.The distnace betweent the lens and the mirror is 10 cm.A small object is kept at a distance of 30 cm from the lens .The final image is