Question

In the displacement method, a convex lens is placed in between an object and a screen. If the magnifications in the two positions are m₁ and m₂ and the displacement of the lens between the two positions is x, then the focal length of the lens is

A. x/m₁ + m₂
B. x/m₁ - m₂
C. x/(m₁ + m₂)²
D. x/(m₁ - m₂)²

Answer 1

The focal length of the lens in the displacement method is x/(m₁ + m₂)². The correct answer is option C.

Step-by-step explanation:

In the displacement method, a convex lens is placed in between an object and a screen. The magnification in each position is given by m₁ and m₂. The displacement of the lens between the two positions is given by x.

According to the displacement method formula, the focal length of the lens is x divided by the sum of the magnifications squared, which is represented by x/(m₁ + m₂)².