NPTEL PRINCIPLE OF CASTING TECHNOLOGY Assignment 5 Answer 2023
NPTEL PRINCIPLE OF CASTING TECHNOLOGY week 5 Answer 2023
1)Which of the statement about the Chills is correct?
A)It is used to increase heat transfer during solidification of casting in mold
B)They are metallic objects
C)They are used to support the core in the mold
D)Both a and b
ANSWER : A
2)Chaplets used during casting is made of
A)Ceramic materials to withstand heat
B)Same material as that of cast metal
C)Ferrous based materials
D)Aluminium or copper to increase heat extraction rate
ANSWER : B
3)The prime function of riser is to
A)Take care of solid shrinkage during casting process
B)Take care of liquid or solidification shrinkage during casting process
C)Ensure that the casting cavity is filled fully
D)Minimize the pouring time of molten metal into the cavity
ANSWER: A
4)Shape factor of casting is defined as -------------. A higher value of shape factor means --------- solidification time of the casting
(Where L, W and t is the length, width, and thickness of casting respectively)
A) (L+W)/t, Higher
B) (L+W)/t, Lesser
C) (L+t)/W, Lesser
D) (L+t)/W, Higher
ANSWER: B
5)Which of the following method is not used for riser design calculations?
A)Caines’s method
B)Modulus method
C)Shrinkage volume method
D)Shatter test method
ANSWER : A
6) Modulus of casting is the ratio of ------------- and higher value of it means ------------ solidification time of the casting.
A)Volume of casting to the surface area of casting, higher
B)Surface area of casting to the volume of casting, higher
C)Volume of casting to the surface area of casting, lower
D)Surface area of casting to the volume of casting, lower
ANSWER: A
7)The tendency of the core to shift from its position in the mold cavity due to buoyancy force experienced by the core is taken care of by the use of
A)Chills Riser
B)Riser
C)Chaplets
D)Runner extension
ANSWER : B
8)Solid shrinkage during solidification of metal is taken care by
A)Riser
B)Skim bob
C)Ensuring directional solidification
D)Shrinkage allowance provided in the pattern
ANSWER : A
In a sand casting operation, the total liquid head is maintained constant such that it is equal to the mould height. The time taken to fill the mould with a top gate is tA. If the same mould is filled with a bottom gate, then the time taken is tB. Ignore the time required to fill the runner and frictional effects. Assume atmospheric pressure at the top molten metal surfaces. The relation between Ta and Tb is
A)tB = 5tA
B)tB = 2tA
C)tB = 3tA
D)tB = 4tA
ANSWER : B
10) A mould having dimensions 100 mm × 90 mm × 20 mm is filled with molten metal through a gate with height ‘h’ and cross-sectional area A, the mould filling time is . The heightis now quadrupled, and the cross-sectional area is halved. The corresponding filling time ist2 . The ratio t2 /t1 is
A)3
B)1
C)4
D)5
ANSWER : 1
COURSE TYPE: Elective
COURSE LEVEL of NPTEL PRINCIPLE OF CASTING TECHNOLOGY
: Undergraduate/Postgraduate
COURSE LAYOUT NPTEL PRINCIPLE OF CASTING TECHNOLOGY
Week 1:Introduction to casting technology,mechanism of solidification,solidification of pure metal and alloys,freeze wave mechanism and solidificaton time,problems solving on solidification
Week 2:Technology of pattern making,Allowances in pattern making,Moulding sands and its ingredients,Testing of molding sands,Sand preparation for casting
Week 3:Technology of mould making,Technology of core making,Special sand moulding process,Organic binders,Special moulding process
Week 4 :Introduction of gating design,Types of gate,Pouring time calculation,Aspiration effects in gating system,Problem solving on gating design
Week 5 :Solidification analysis,Risering methods,Shape factor,Feeding & Chills effect,Problem related to riser design
Week 6 :Special casting process1,Special casting process 2,Special casting process 3,Technology of melting,Melting practices
Week 7 :Melting & Casting of cast metal,Melting practice for gray iron,Melting practice for Malleable iron & S.G iron,Casting of steel & alloy steel
Week 8 :Casting practices for non-ferrous metals & alloys,Fettling of castings,Heat treatment of castings,Heat treatment practices for cast iron & non-ferrous metals & alloys,Casting defects,Diagnostics of casting defects
CRITERIA TO GET A CERTIFICATE
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