1.When a loaded test tube floats vertically with 1 /3 and 1 / 4 of the lengths inside two liquids, then the ratio of the densities of the two liquids is

2.A common hydrometer reads specific gravity of liquids. Compared to 1.6 on the stem, the mark 1.5 will be

3.An open U-tube of uniform cross-section contains mercury. When 27.2 cm of water column is poured into one limb, then the difference in levels of liquids of two sides is

4.The reading of a spring balance when a block is suspended form it in air is 60 N. This reading is changed to 40 N when the block is submerged in water. The specific gravity of the block is

5.A concrete sphere of radius R has a cavity of radius r which is packed with saw-dust. The specific gravities of concrete and saw dust are 2.4 and 0.3 respectively.The sphere floats with its entire volume submerged under water. The ratio of mass of concrete and the mass of saw dust is