Lens and displacement method

When the distance between the object and the screen is more than 4 f . We can obtain image of the object on the screen for the two positions of the lens. If is called displacement method. In one case, the image is magnified and in the other case, it is diminished. If I_(1) and I_(2) be the sized of the two images, then the size of the object is

If I_(1) and I_(2) be the size of the images respectively for the two positions of lens in the displacement method, then the size of the object is given by

If x_(1) is the size of the magnified image and x_(2) is the size of the diminsghed image in lens displacement method, then the size of the object is

Assertion: In displacement method of finding focal length of a convex lens its magnification in one position of lens is +2, then magnification in another position of lens should be -1/2. Reason:This method can't be applied for a concave lens.

Thin lens (Part-1) |Types of thin lens|Nature of lens|Lens displacememt method

Cutting OF Lens|| Shifting OF Parts OF Lens|| Displacement Method

A thin converging lens of focal length f is placed bewteen an obejct an a screen at a distance D apart, (displacement method)

Displacement Method||Eye