a convex lens of power 4d is placed at a distance of 40cm

power 4dOptical power is also referred to as dioptric power, convergence power, refractive power, or refractive power. It is equal to P = 1 f. Dioptre Formula . The Dioptre formula is used toMagnum Corporation is the first company licensed to operate the exciting 4D Classic, including 4D Jackpot, 4D Jackpot Gold and Magnum Life. Social Responsibility Since inception in 1968,