What is the power of a combination of lenses?
Power of lens:
A convex lens of power 5 D and a concave lens of power 7.5 D are placed in contact with each other. What is the :(a) power of this combination of lenses?(b) focal length of this combination of lenses?
(a) What do you understand by the power of a lens? Name one factor on which the power of a lens depends.
(b) What is the unit of power of a lens? Define the unit of power of a lens.
(c) A combination of lenses for a camera contains two converging lenses of focal lengths 20 cm and 40 cm and a diverging lens of focal length 50 cm. Find the power and focal length of the combination.
A convex lens of power 5 D and a concave lens of power 7.5 D are placed in contact with each other. What is the: (a) Power of this combination of lenses? (b) Focal length of this combination of lenses ?