16.A body weighs 160 g in air and 130 g in water and 136 g in oil. The specific gravity of oil is:

17.The rise of water in a capillary tube when kept vertical in water whose radii is � th of that capillary tube which when kept vertical water rise in it up to a height of 3 mm is:

18.Water flows along a horizontal pipe whose cross-section is not constant. The pressure is 1 cm of Hg where the velocity is 35 cm/s. At a point where the velocity is 65 cm/s, the pressure will be:

19.Water from inside the earth rises through the trunk of a big tree to leaves high up. The main reason for this is:

20.Water is flowing through a tube of non-uniform cross-section. If the radius of the tube at the entrance and exit is 3: 2, then the ratio of velocity of liquid entering and leaving the tube is: