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.

An erect image 2.0 cm high is formed 12 cm from a lens, the object being 0.5 cm high. Find the focal length of the lens.

A cocave lens forms the image of an object such that the distance between the object and image is 10 cm and the magnification produced is 1/4. the focal length of the lens will be

A cocave lens forms the image of an object such that the distance between the object and image is 10 cm and the magnification produced is 1/4. the focal length of the lens will be

A concave lens forms the image of an object such that the distance between the object and image is 10 cm and the magnification produced is 1//4 . The focal length of the lens will be

A concave lens forms the image of an object such that the distance between the object and image is 10cm and the magnification produced is 1/4. The focal length of the lens will be

An object is placed at a distance of 30 cm from a convex lens. A real image of magnification 1.5 is formed. Find the location of the image and the focal length of the tens.

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: