A student obtained a sharp image of a lighted candle on a screen using a 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.

The diagrams A and B represent the following relationship:

Identify the parts labeled 1 and 2 in the adjoining figure

When you add sodium hydrogen carbonate to acetic acid in a test tube, a gas liberates immediately with a brisk effervescence. None the gas and describe the method of its testing in the laboratory.

Mention about the four events that occur during binary fission in amoeba.