10) Heat transfer in liquids and gases is essentially due to
Answer is:
Convection
Related RRB JE Mechanical Question Paper 2014 (Set-1) with Answer Key
Answer is:
Silica
Explanation:
Silica sand in form of granular quarts is the main constituent of molding sand having enough refractoriness which can impart strength, stability and permeability to molding and core sand. But along with silica small amounts of iron oxide, alumina, lime stone (CaCO3), magnesia, soda and potash are present as impurities.
Answer is: