Real image of an object are formed on the fromed on the two positions of a lens separated by a distance`60cm`
`If the distance between object and screen is`180cm`then ,the focal length of the lens is:

Real image of an object are formed on the fromed on the two positions of a lens separated by a distance 60cm The ratio between the sizes of the two image will be:

Real image of an object are formed on the fromed on the two positions of a lens separated by a distance 60cm The Images in the two cases have sizes 0.4cm and 0.9cm .the size of the object will be :

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:

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:

The distance between the object and the screen is d (greater than 4 times the focal length of a convex lens). Real images of the object are obtained on the screen for two positions of the lens that are separated by distance x apart. The ratio of size of the images in the two positions of the lens are

A convex lens forms an image of an object on a screen 30 cm from the lens. When the lens is moved 90 cm towards the object, then the image is again formed on the screen. Then, the focal length of the lens is

A convex lens forms an image of an object on a screen 30 cm from the lens. When the lens is moved 90 cm towards the object, then the image is again formed on the screen. Then, the focal length of the lens is

A screen is placed 80 cm from an object. The image of the object on the screen is formed by a convex lens placed between them at two different locations separated by a distance 20 cm. Determine the focal length of the lens.