Question 1

Pattern draft for internal surfaces is (in mm/m)&#10;A)10 -- 30&#10;B)50 - 80&#10;C)40 - 70

Accepted Answer

Pattern draft for internal surfaces typically ranges from 40 to 70 mm/m. This allows for easier removal of the pattern from the mold without damaging the mold's surface.

Question 2

On drying the shrinkage of wood is least&#10;A)along the grains&#10;B)across the grains&#10;C)along the direction of tangent to the annular rings

Accepted Answer

Wood shrinks least along the grain (longitudinally) because the cell structure is oriented in this direction, making it more stable and less susceptible to moisture changes compared to across the grain or tangentially.

Question 3

Contraction of metal starts at the end of&#10;A)mushy stage&#10;B)plastic stage&#10;C)liquid stage&#10;D)solid stage

Accepted Answer

Contraction of metal starts at the end of the mushy stage, where the metal is partially solid and partially liquid, beginning the transition to a fully solid state.

Question 4

In radiography test on castings which of the following rays are never used?&#10;A)X-rays&#10;B)beta rays&#10;C)gamma rays&#10;D)all of the above

Accepted Answer

Beta rays are not used in radiography testing of castings because they have low penetration power and are not effective for inspecting the internal structure of materials. X-rays and gamma rays are commonly used due to their high penetration capabilities.

Question 5

Metal moulds are used in&#10;A)dry sand moulding&#10;B)green sand moulding&#10;C)die casting process&#10;D)loam moulding

Accepted Answer

Metal moulds are primarily used in the die casting process, where molten metal is injected into a die or a mould made of metal under high pressure. This process is known for producing precise, smooth, and textured-surface metal parts rapidly.

Question 6

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&#10;A)low mould hardness&#10;B)insufficient reinforcement&#10;C)low green strength&#10;D)any of the above

Accepted Answer

The defect known as 'drop' can occur due to various reasons including low mould hardness, insufficient reinforcement, and low green strength. Each of these factors can contribute to the upper surface of the mould cracking and pieces of sand falling into the molten metal.

Question 7

Investment casting finds application in all of the following EXCEPT&#10;A)Jet engine nozzles&#10;B)Milling cutters&#10;C)Buckets for superchargers&#10;D)Gold ornaments

Accepted Answer

Investment casting is not used for gold ornaments because they are typically made using other methods such as lost-wax casting or die casting.

Question 8

Lowest pouring temperature alloy is&#10;A)Phosphor bronze&#10;B)Cupro nickel alloy&#10;C)Monel metal&#10;D)Tin bronze

Accepted Answer

The answer of Lowest pouring temperature alloy is&#10;A)Phosphor bronze&#10;B)Cupro nickel...

Question 9

The residual stresses in casting occur due to&#10;A)sand particles being taken into molten metal while pouring&#10;B)the insufficient gate size&#10;C)the differential solidification rate of thin and thick sections of casting&#10;D)none of the above

Accepted Answer

Residual stresses in castings primarily occur due to the differential solidification rate of thin and thick sections of the casting. This difference in cooling rates leads to uneven contraction, which in turn causes residual stresses.

Question 10

Local stress relief treatments are generally given to&#10;A)small castings&#10;B)non-ferrous castings&#10;C)all castings&#10;D)too large castings

Accepted Answer

Local stress relief treatments are generally given to too large castings because they are more prone to residual stresses due to their size and complexity, which can lead to defects or distortions if not properly managed.

Question 11

Which of the following is used on moulds for magnesium castings to prevent metal mould reactions?&#10;A)Boric sulphur&#10;B)Molasses&#10;C)Charcoal&#10;D)all of the above

Accepted Answer

The answer of Which of the following is used on...

Question 12

Silica is the second most important constituent of moulding sand which provides&#10;A)binding strength&#10;B)refractoriness&#10;C)chemical resistance&#10;D)none of the above

Accepted Answer

The answer of Silica is the second most important constituent...

Question 13

Flash occurs on diecastings at the&#10;A)gatting system&#10;B)ejection pins&#10;C)vents between the dies&#10;D)parting surface of two dies

Accepted Answer

The answer of Flash occurs on diecastings at the&#10;A)gatting system&#10;B)ejection...

Question 14

The methods of casting for producing ornamental pieces are&#10;A)pressed and slush casting&#10;B)slush and gravity casting&#10;C)gravity and semi permanent mould casting&#10;D)none of the above

Accepted Answer

The answer of The methods of casting for producing ornamental...

Deck 11: Casting and Moulding Processes: Techniques and Defects