power 4d6. A convex lens of power +6 D is placed in contact with a concave lens of power –4D. What will be the nature and focal length of this combination ? (a) convex, 100 cm (b) convex, 50 cmhave found 30749 great 4d Desn Powerpoint templates for free. More animated ppt about 4d Desn free Download for commercial usable,Please visit . Follow