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 biconvex lens is used to project a slide on screen. The slide is 2 cm high and placed at 10 cm from the lens. The image is 18 cm high. What is the focal length of the lens?

A biconvex lens is used to project a slide on screen. The slide is 2 cm high and placed at 10 cm from the lens. The image is 18 cm high. What is the focal length of the lens?

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 object is kept at 60 cm in front of a convex lens. Its real image is formed at 20 cm from the lens . Find the focal length and power of the lens.

The image of an object placed at 60 cm in front of a lens is obtained on a screen at a distance of 120 cm from it. Find the focal length of the lens. What would be the height of the image of the object is 5cm high ?

The image of the needle placed 10 cm from a lens is formed on a wall 20 cm on the other side of the lens. Find focal length of the lens and size of image formed, if the size of object needle is 2.5 cm .

An object is kept at 20 cm in front of a convex lens and its real image is formed at 60 cm from the lens . Find The focal length and power of the lens .