The distance between an object and a screen is 100 cm. A lens can produce real image of the object on the screen for two different position between the screen and the object. The distance between these two positions is 40 cm. If the power of the lens is close to `((N)/(100))D` where N is integer, the value of N is ___________.

The distance between an object and the screen is 100cm. A lens produces an image on the screen when the lens is placed at either of the positions 40cm apart. The power of the lens is nearly

The distance between object and the screen is D. Real images of an object are formed on the screen for two positions of a lens separated by a distance d. The ratio between the sizes of two images will be:

A lens produces a virtual image between the object and the lens. Name the lens.

The minimum distance between an object and its real image formed by a convex lens is

The minimum distance between an object and its real image formed by a convex lens is

The magnifications for two positions of image of the same lens are 3 and 2, of a fix point object on a fix screen when the distance between the two positions of lens is 30 cm . The focal lengths of the lens is

A convex lens forms a real image of an object for its two different positions on a screen. If height of the image in both the cases be 8 cm and 2 cm , then height of the object is

A lens is placed between a source of light and screen. It forms real image on screen for two different positions. If height of one image is 20 cm and the other is 80 cm, then the height of source of light (in cm) is_____.

In the displacement method , a convex lens is placed in between an object and a screen . If one of them magnification is 3 and the displacement of the lens between the two positions is 24 cm , then the focal length of the lens is :-

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