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?

What is the position of image when an object is placed at a distance of 12 cm from a convex lens of focal length 12 cm?

Describe the nature of image formed when an object is placed at a distance of 30 cm from a convex lens of focal length 15 cm.

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

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.