Two lenses have power of 2D and -4D. An object is kept at a distance of 100 cm from each of the above lenses. Calculate
image distance?

An object is placed at a distance of f//2 from a convex lens .The image will be

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

An object is at a distance of 5 m from a convex mirror of focal length 10 cm.Where is he image formed ?

Two lenses have powers + 1 D and - 2 D respectively ,The power of combination si:

Two lenses of power 15.5 D and -5.5 D are placed in contact.What is teh focal length of the combbination?

A compound microscope is used to enlarge an object kept at a distance of 0.03 m from its objective, which consists of several convex lenses and has focal length 0.02 m .If a lens off focal length 0.1 m is removed from the objective, find out the distance by which the eye-piece of the microscope must be moved to refocus the image.

Two lenses having powers + 6 D and - 4D are placed in contact.The power of the combintin is

A convex lens of power 4D is placed at a distance of 40 cm from a wall at what distance from the lens should a candle be placed so that its image is formed on the wall?

Two thin lenses of pwer +5D and -3D are in contact. What is the focal length of the combnation?

Calculate the position of image, when an object is placed at a distance of 15 cm from a convex mirror having focal length 0.45 m.