Which of the following lenses would you prefer to use while reading small letters found in a dictionary?
A convex lens of focal length 5 cm. A convex lens gives an erect and magnified image of an object when it is placed between the optical centre and focus of the lens. Also, magnification is more for convex lenses having shorter focal length. Therefore, for reading small letters, a convex lens of focal length 5 cm should be used.