The power of a lens is +4D. Find the focal length of

power 4dPower Toto 655 Hot & Cold Numbers. You probably noticed that some numbers just seem to appear in every other draw! These frequently drawn numbers are known asA convex lens of power 4D is kept in contact with a concave lens of power 3D, the effective power of combination will be . View Solution; Knowledge Check. A convex lens of focal length 40 cm