A point source of light is located at a distance of 2f from a converging lens with a focal length of f . On the opposite side of the lens, the intensity will be maximum at a distance of

Step-by-step solution

Using the lens formula, 1 v - 1 u = 1 f Given the object distance u = -2f , we have: 1 v - 1 -2f = 1 f 1 v + 1 2f = 1 f 1 v = 1 f - 1 2f = 1 2f v = 2f The rays from the point source converge at the image point, which is at a distance of 2f on the opposite side of the lens. Since all the refracted rays converge at this point, the light energy is concentrated in a minimum area. Therefore, the intensity of light will be maximum at a distance of 2f .