An object 4 cm high is placed at a distance of 10 cm from a convex lens of focal length 20 cm. Find the position, nature and size of the image. Draw the diagram to represent the position.

At what distance from a converging lens of focal length 14 cm must an object be placed in order that an image of magnification 1 will be produced?

State and explain the New Cartesian Sign Convention for spherical lenses.

A small object is so placed in front of a convex lens of 5 cm focal length that a virtual image is formed at a distance of 20 cm. Find the magnification.

Find the position and nature of the image of an object 8 cm high and 10 cm in front of a convex lens of focal length 6 cm.