Time left 1 In which of the following activities silicon carbide is used? Making cement and glass Disinfecting water of ponds cutting very hard substances Making casts for statues 2 The property of a substance to absorb moisture from the air on exposure is called osmosis deliquescence efflorescence desiccation 3 The gases used in different types of welding would include oxygen and hydrogen oxygen, hydrogen, acetylene and nitrogen oxygen, acetylene and argon oxygen and acetylene 4 The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is Argon Xenon Helium Krypton 5 Which of the following is used as a lubricant? Graphite Silica Iron Oxide Diamond 6 Tetraethyl lead is used as pain killer fire extinguisher mosquito repellent petrol additive 7 The average salinity of sea water is 3% 3.50% 2.50% 2% 8 The variety of coal in which the deposit contains recognisable traces of the original plant material is bitumen anthracite lignite peat
Skip This