A thin converging lens is placed between an object and a screen whose position are fixed. There are two positions of the lens at which the sharp image of the object is formed on the screen. Find the transverse dimension of the object if at one position of the lens the image dimension equal `h' = 2.0 mm` and at the other, `h'' = 4.5 mm`.

A thin converging lens is placed between an object and a screen whose the sharp image of the object is formed on the screen. Find the transverse diamension of the object if at one position of the lens the image diamension equals h' = 2.0 mm and at the other, h'' = 4.5 mm .

A thin convergent lens is placed between an object and a screen whose positions are fixed. There are two positions of a lens at which sharp image of the object is formed on the screen. If the size of the images in the two cases are 2 mm and 4.5 mm then the size of the object should be:-

(a) A screen is kept at a distance of 1m from the object. A converging lens between the object and the screen, when placed at any of the two positions which are 60cm apart, forms a sharp image of the object on the screen. Find the focal length of the lens. (b) In the two positions of the lens, lateral size of the image is 4cm and 9cm. Find the size of the object.

A convex lens is placed between an object and a screen which are at a fixed distance apart for one position of the lens. The magnification of the image obtained on the screen is m_(1) . When the lens is moved by a distance d the magnification of the image obtained on the same screen m_(2) , Find the focal length of the lens.

If the image formed by a convex lens is of the same size as that of the object, what is the position of the image with respect to the lens?

The height of the image formed by acoverign lens on a screen is 8cm ,For the same position of the object and the screen again an Image of size 12.5cm is formed on the screen by shifting the lens.The height of the object.

A convex lens forms a real image on a screen placed at a distance 60 cm from the object. When the lens is shifted towards the screen by 20 cm , another image of the object is formed on the screen. The focal length of the lens is :

A source of light is located at a disatnce l = 90 cm from a screen. A thin converging lens provides the sharp image of the source when placed between the source of light and the screen at two positions. Determine the focal length o fthe lens if (a) the distance between the two positions of the lens is Delta l = 30 cm , (b) the transverse diamensions of the image at one position o fthe lens are eta = 4.0 greater than those at the pther position.