Negative power indicates that it is a ___.
concave lens
convex lens
combination two convex lenses
Power=1Focal length ⇒ Since concave lens have negative focal length, power of concave lens is also negative.
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 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?