What is the principle of the lens displacement method?

The lens displacement method is based on the principle of the thin lens formula.

The lens displacement method is a technique used to determine the focal length of a thin lens. It is based on the principle of the thin lens formula, which states that 1/f = 1/u + 1/v, where f is the focal length of the lens, u is the object distance, and v is the image distance.

To use the lens displacement method, a thin convex lens is placed on a stand and a distant object is placed in front of it. The position of the object is adjusted until a clear image is formed on a screen behind the lens. The distance between the object and the lens (u) and the distance between the image and the lens (v) are measured.

The focal length of the lens can then be calculated using the thin lens formula. However, to increase the accuracy of the measurement, the experiment is repeated with the lens displaced by a small distance. The new object and image distances are measured, and the focal length is calculated again.

By taking the average of the two focal length measurements, a more accurate value can be obtained. The lens displacement method is a simple and effective way to determine the focal length of a thin lens, and is commonly used in physics experiments and optics research.