Image Properties for Different Positions In Different Lenses|Concave Lens|Combination Of Lenses

Image Formation By Concave Mirror In Different Position Of Object

Image Formation By Convex Lens In Different Position Of Object

Image Formation By Concave Lens In Different Position Of Object

Power and Combination OF Lenses and Mirrors

Rules For Obtaining Images Formed By Concave Lenses |Lens Formula|Magnification Produced By Lenses |Practice Exercise|Power Of A Lens|Power Of A Combination Of Lenses|Summary

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?