A lens forms a real image of an object. The distance from the object to the lens is x cm and that from the lens to the image is y cm. The graph shows the variation of y with x.
It can be deduced that the lens is

A convex lens of focal length 16 cm forms a real image double the size of the object. The distance of the object from the lens is

A lens forms a real image 3 cm high of an object 1 cm high. If the separation of object and image is 15 cm, find the focal length of the lens.

A convex lens forms a real image of the object when the lens is at a distance of 1 m from the object. The size of the image is 3 times that of the object. The position of the object and the screen are kept fixed but the distance of lens from the object is doubled. The image is now one half of the size of the object, the focal length of the lens is

The distance of the image from the focus of a lens is x and that of object is y . The nature of the graph y versus x is

A lens forms real image of an object 20 cm away from lens. A second lens is kept in contact with this lens, then image shifts 10 cm towards the lens combination. Find the power of another lens.

The distance between the object and its real image from the convex lens is 60 cm and the height of image is two times the height of object . The focal length of the lens is

The distance between the object and its real image from the convex lens is 60 cm and the height of image is two times the height of object . The focal length of the lens is