Question

A student obtained a sharp image of a lighted candle on a screen using convex lens. Now he wants to focus a distant lamp on a far away electric pole in which direction should the lens be moved for this purpose with respect to the screen , to get a sharp image on the screen. Justify your answer

Answer 1

The conevx lens converges rays of light and focuses the image at screen . if object is far away , we can take lights coming from infinity and so we should move convex lens towards screen so object be farther away and light rays coming from infinity .
convex lens creates a clear and sharp image from lights coming from infinity.