A student wants to project the image of a candle flame on the walls of school laboratory by using a lens: (a) Which type of lens should he use and why?

a) The student should use a convex lens because with the help of a convex lens, he would be able to project an image on the walls because a convex lens will form a real image.
b) (i) In order to form a magnified image on the wall, the candle flame should be placed between F and 2F from the lens. (ii) In order to form a diminished image on the wall, the candle flame should be placed at a distance greater than 2F from the lens.