We can burn a piece of paper by focussing the sunrays by using a particular type of lens. Name the type of lens used for this purpose.

Q. We can burn a piece of paper by focusing the sun rays by using a particular type of lens. Name the type of lens used for the above purpose.

Q. The heat of sun focussed by a convex lens on a piece of paper is capable of

Q. A student obtained a sharp image of the grill of a window on a screen, using a convex lens. For getting better results, the teacher suggested focussing of a distant tree instead of the grill. In which direction should the lens be moved for this purpose?

Q. Name the type of lens used to correct this defect.

Q. A lens is thicker in the middle than at the edges. Can it be used to burn a piece of paper by using sunlight?