A steel block having an internal cavity weighs 234 g in air and 197 g in water. If the density of steel is 7.8 g cm-3, then the volume of the cavity is

Weight of water displaced by steel block= Loss of weight of block in water= (234 - 197)gf = 37 gfVolume of water dispalced = 37 cm3This is the volume of the block with cavity.Volume of block without cavity = 2247.8 cm3 = 30 cm3Volume of cavity = (37-30) cm3 = 7 cm3