The defect known as 'drop' occurs when the upper surface of the mould cracks and pieces of sand fall into the molten metal. This defect occurs due to

Related MCQs

• During the passage of molten metal through the coke, the carbon percentage of the molten metal increases. The absorption of carbon depends on
• A casting process which can produce cylinders by inserting cores into molten metal poured in the mould is
• A defect in castings in which a discontinuity is formed due to the imperfect fusion of two streams of metal in the mould cavity is known as
• The property of sand to withstand the high temperature of the molten metal without fusing or breakdown is known as
• If dross and slag along with the liquid metal reach the mould cavity they produce the defect known as
• A mould cracks after drying. It indicates
• Sand acquires a predetermined shape under pressure and retains the same when pressure is removed. This is due to the property of sand known as
• As compared to green sand in shell moulding cooling rate of cast metal is slow. Hence as compared to green sand castings, shell moulded castings will have
• The tool used to make small holes in the sand mould to allow passage of gases/steam is known as
• Rammer used for moulding the sand in large mould known as