About This Simulation

This interactive simulation demonstrates the lens displacement method for determining the focal length of a convex lens. The method involves:

• Placing an object and screen a fixed distance D apart
• Moving a convex lens between them to find two positions where a sharp image forms on the screen
• Measuring the distance d between these two lens positions
• Calculating the focal length using the formula: f = (D² - d²)/(4D)

Adjust the sliders to change the object-screen distance (D) and lens displacement (d) to see how these parameters affect the focal length calculation.