4D History - 4D Statistic

power 4dTo find the focal length of the combination of two thin lenses in contact, we can follow these steps: Step 1: Identify the Powers of the Lenses We have two lenses: - Lens 1 has a power ( P1 = +4A 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