Chemistry

  1. Which one of the following is incombustible ? H2 CCl4 C2H2 S 2. The softness or hardness of a grinding wheel depends upon the type & amount of bonding material used. For general purpose cutter grinding __________ grinding wheel is normally used. hard soft silicon carbide aluminium oxide 3. Tin based white metals are used, where bearings are subjected to high pressure & load. low pressure & load. high temperature. large surface wear. 4. Friction factor for fluid flow in pipe does not depend upon the pipe length. pipe roughness. fluid density & viscosity. mass flow rate of fluid. 5. All of the following alloying elements of steel increases hardness but sacrifice ductility, except nickel vanadium molybdenum chromium