The graph shows how the magnification m produced by a thin lens varies with image distance v. What is the focal length of the lens used?

The graph shows how the magnification m produced by a thin lens varies with image distance v. What is the focal length of the lens used?

A divergent lens has focal length of 20 cm. At what distance should the object fromthe lens be placed so that an image is formed 10 cm away from the lens? What is themagnification produced, by the lens

Look at the diagram below. The light source is 0.27 m from the lens. The screen is moved to a distance of 0.11 m from the centre of the lens so an image of the light source is seen at the screen.Calculate the focal length of the lens. Express answer to three decimal places,use SI units.

An object 50 cm tall is placed on the principal axis of a convex lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm from the lens. Calculate the focal length of the lens upto two places of decimal.

A doctor has prescribed a corrective lens of power +1.5 D. What is the focal length and nature of the lens?