Two lenses of powers 10D - 5D are placed in contact
Calculate the power of the new lens.

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

If two lenses of power +1.5 D and +1.0 D are placed in contact ,then the effective power of combination will be

Two lenses of power +10 D and -5 D are placed in contact. Where should an object be held from the lens,so as to obtain a virtual image of magnification 2?

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

Two lenses of powers+15D and -5D are in contact with each other. What is the focal length of combination?

Define power of a lens

…is the unit of power of the 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.