Production Technology Past Paper PDF

07. Production Technology 3. Chills are used in casting mould to 1. Metal Casting Processes (a) achieve directional solidification...

07. Production Technology 3. Chills are used in casting mould to 1. Metal Casting Processes (a) achieve directional solidification (b) reduce blow holes. 1. Investment casting uses a pattern made up of- (c) reduce the freezing time (a) Wood (b) Metal (d) increase the smoothness of the casting surface (c) Wax (d) Plastic Mizoram PSC JE 2019 (Paper-III) NPCIL 08.11.2019 (9.00-11.00 am) WBPSC 2018, 1999, GPSC 09.10.2016 HPCL JE 8-11-2019, ISRO SDSC 08.04.2018 GPSC Insp. of Motor Vehicle 19.10.2016 DMRC 18.02.2017 RRB JE [Exam Date- 27.08.2015 (Shift-II)] Karnataka PSC RTO (Mech.) 10.07.2016 Ans. (a) : A Chill is an object used to promote Mizoram PSC 2015 (Paper-3) solidification in a specific portion of a metal casting RRB JE [Exam Date-27.08.2015 (Shift-I)] mould. When the geometry of the moulding cavity ESE-2010, WBPSC 2003, 1999 prevents directional solidification from occurring Ans. (c) : In Investment casting or lost wax casting or naturally, a chill can be strategically placed to help precision casting pattern are made of wax, mercury promote the solidification. sometimes plastics. 4. Which one of the following is the correct Advantage– statements ? (i) Complex shape can be produced. Gate is provided in moulds to (ii) Very fine details and thin section can be produced. (a) feed the casting at a constant rate (iii) Very close tolerance and better surface finish can (b) give passage to gasses be produced. (c) compensate for shrinkage (iv) Tolerance dimension about 0.03 to 0.05. (d) avoid cavities Applications–Vane or blade of turbines (gas turbines) HPSSC JE 10.04.2021 stainless steel valve and impeller for turbo charger. DMRC 2016 (Paper-I) 2. A Taper provided on the pattern for is easy RRB JE [Exam Date : 29-08-2015 (Shift-II)] RRB JE [Exam Date : 14-12-2014 (05 Yellow Paper)] and clean withdrawal from the mould is known as ESE-2007 (a) Shaking allowance Ans. (a) : Gate is provided in mould to feed the casting (b) Distortion allowance at a constant rate. (c) Machining allowance The gate is actual entry point through which molten (d) Draft allowance metal entries in the mould cavity. GPSC AMVI 2020 There are four gating system used in casting. GPSC AMVI (ME) 24-12-2016  Top gate UPRUVNL JE 2016 (Shift-I)  Bottom gate WBPSC 2016, 2007  Parting gate ISRO IPRC 28.08.2016, MP Sub-Engineer 2015  Step gate ISRO VSSC 07.04.2012 5. Which of the following statements about SSC JE 2009 unused heat from an energy source in a steam Ans. (d) : The taper provided on the pattern for its easy power plant is correct? and clean withdrawal from the mould is called draft. (a) Is not used by economiser Draft/Taper allowances provided for easy removal of (b) Is used to cool the steam in condensor pattern without damaging mould. (c) Is directly released to atmosphere o (d) Is used to preheat feed water and superheat 1 the generated steam The average value of the taper allowance is    2o 2 UPSSSC JE 19.12.2021 Internal surface require more taper when compared to Ans. (c) : The part of heat which is directly released to external surface cause for the external surface the mould atmosphere through chimney, is unused heat in a steam strength is more compared to internal surfaces. power plant. Production Technology 733 YCT 6. Which one of the following materials will Ans. (a) : In permanent mould casting because of the require the largest size of riser for the same metallic mould used. This process produces a fine casting? grained casting with superior mechanical properties. (a) Aluminium (b) Cast iron So, some of the components that are produced in (c) Steel (d) Copper permanent mould casting are automobile pistons, GPSC 09-10-2016 stators, gear blanks, connecting rods, aircraft fitting, GPSC Insp. of Motor Vehicle 19.10.2016 cylinder blocks etc. ESE-1995 Slush casting produces- jewellery, ornamental objects and statues. Ans. (a) : Liquid and solidification shrinkage is maximum for aluminium which can be compensated by Centrifugal casting is used for making bigger size riser while overall shrinkage is maximum for steel. hollow symmetrical pipes. There are three type of centrifugal casting (i) True centrifugal casting (ii) Semi- 7. The property which makes the moulding sand centrifugal casting (iii) Centrifuging. capable of withstanding high temperatures of molten metal without the fusion of sand is- 10. Match plate pattern is used for : (a) Refractoriness (b) Porosity (a) Green sand moulding (b) Pit moulding (c) Cohesiveness (d) Plasticity (c) Machine moulding (d) Bench moulding NPCIL 07.11.2019 (9.00-11.00 am) HPCL JE 07-11-2019 (Shift-2) HPCL JE 07.11.2019 Shift-I NPCIL 07.11.2019 RRB SSE Exam Date- 01.09.2015 Shift–II SSC JE 03 March, 2017, Shift-I MPSC AMVI 2005 Ans. (c) : Match plate pattern mostly used for machine moulding produce complex shape of the object in mass Ans. (a) : Refractoriness is the property of moulding production. sand which makes the moulding sand capable of The number of pattern can be split along parting line, withstanding high temperatures of molten metal without and they will be added on both side of match plate fusion of sand which provides the better casting surface along with gating element. and easier cleaning of the casting. Other properties of moulding sand– 11. Small amount of carbonaceous material (i) Green strength, (ii) Dry strength, (iii) Hot strength, sprinkled on the inner surface of mould cavity is called : (iv) Permeability, (v) Thermal stability, (a) Backing sand (b) Facing sand (vi) Flowability, (vii) Collapsibility, (c) Green sand (d) Dry sand (viii) Adhesiveness, (ix) Cohesiveness, (x) Reusability, (xi) Conductivity, (xii) Easy to preparation and control. GPSC Insp. of Motor Vehicle 19-10-2016 GPSC 09.10.2016 8. Hot tear refers to- RRB JE [Exam Date- 30.08.2015 (Shift-III)] (a) Casting defect (b) Process of fabrication of sheet metal Ans. (b) : Small amount of carbonaceous material sprinkled on the inner surface of mould cavity to give a (c) Process of heat treatment better surface finish is called facing sand. (d) Weathering of nonferrous metals A sand used for facing of the mould is called facing NPCIL 07.11.2019 (9.00-11.00 am) sand. It is specially prepared sand from silica sand and HPCL JE 7.11.2019 Shift-I clay, without the addition of used sand. SSC JE 1 March, 2017 Shift-I 12. The methods of casting for producing Ans. (a) : Hot tears are internal or external ragged ornamental pieces are _____. discontinuities or crack on the casting surface. Caused (a) slush and gravity castings by rapid contraction occurring immediately after the (b) pressed and slush castings metal solidified. (c) semi-permanent mould and pressed castings Some important casting defects are– (d) gravity and semi-permanent mould castings (i) Shrinkage (ii) Porosity GSECL 23-02-2020 (Shift-2) (iii) Scar (iv) Blowhole RRB JE [Exam Date- 29.08.2015, (Shift- II)] (v) Drop (vi) Dirt ESE-2011 (vii) Buckle (viii) Rat tail Ans. (b) : The methods of casting for producing (ix) Mould Shift (x) Metal penetration ornamental pieces are pressed and slush casting. (xi) Cold shut and misrun  The slush casting is a special application involving 9. Gears are casted by- the use of a permanent mould. (a) Permanent mould casting  It is used for casting low melting temperature alloys. (b) Slush casting  This method is only adopted for ornaments and tags (c) Centrifugal casting of non-ferrous alloys. (d) All of the options  Pressed casting is another method of producing NPCIL 08.11.2019 (9.00-11.00 am) hollow casting from permanent moulds but differs Mizoram PSC 2019 (Paper-I) from gravity die casting and slush casting in GSSB ITI Supervision Inst. (Auto) 18.01.2015 operation. It uses close fitting cores. Production Technology 734 YCT 13. Chaplet is used to : (a) Increase the cooling rate of molten metal (b) Decrease the cooling rate of molten metal Here, (c) Compensate the shrinkage V = Volume of air passing through the specimen (d) Support the core (cm3/min) CSEB AE 2018, SSC JE 2015, 2007 H = Height of standard specimen. (cm) JK SSB JE (103) 2014, ESE-2001 P = Pressure of the air (kg/cm2) Ans. (d) : Chaplet is used to support the core A = Cross-sectional area of cylindrical specimen (cm2) It is made up of same material as that of casting so that 17. An allowance that is given along the vertical it get dissolved with the same and after solidification walls of the pattern for ease of withdrawal of the core is taken out separately. pattern from sand is known as : (a) Shrinkages allowance 14. In die casting, machine allowance is (b) Machining allowance (a) not provided (b) small (c) Draft allowance (c) large (d) very large (d) Chamber allowance Mizoram PSC 2019 (Paper-1) ISRO VSSC 28.08.2016 WBPSC 2018 RRB SSE [Exam Date : 01-09-2015 (Shift-II)] RRB JE [Exam Date- 26.08.2015, (Shift-III)] Ans : (c) Draft allowance- It is given so that the Ans. (a) : Die casting may be defined as that casting pattern can be easily removed from the moulding which uses the permanent mould (die) and the molten material tightly packed around it without changing the metal is introduced into it by means of pressure. In die mould cavity. casting, machine allowance is not provided. 15. In a centrifugal casting method: (a) core is made of sand (b) core is made of ferrous metal (c) core is made of nonferrous metal (d) no core is used 18. Misrun is a casting defect which occurs due to– UPRVUNL JE 2015 (a) Very high pouring temperature of the metal RRB JE [Exam Date : 14-12-2014 (04 Green Paper)] (b) Insufficient fluidity of the molten metal ESE-2007 (c) Absorption of gases by the liquid metal Ans. (d) : Centrifugal casting is a process where the (d) Improper alignment of the mould flasks mould is rotated rapidly about its central axis as the RRB JE [Exam Date : 29-08-2015 (Shift-I)] metal is poured into it because of the centrifugal force, a ESE-1996 continuous pressure will be acting on the metal as it Ans : (b) Misrun is a casting defect which occurs due to solidifies. insufficient fluidity of the molten metal. Centrifugal Casting are of three types–  When the metal is unable to fill the mould cavity 1. True Centrifugal Casting completely and thus leaves unfilled cavities, it is 2. Semi– Centrifugal Casting called as misrun defect. 3. Centrifuging  When two streams of liquid metal will not fuse properly and will form a discontinuity in the casting is cold shut. 19. In which of the following are metal moulds used– (a) Green sand mould (b) Dry sand mould (c) Die casting process (d) Loam moulding RRB JE [Exam Date : 29-08-2015 (Shift-I)] ESE-2006 Ans : (c) Metal moulds are used in die-casting process. Die casting– Die casting involves the preparation of 16. The property of sand due to which it evolves a components by injecting molten metal at high pressure great amount of steam and other gases is called: into a metallic die. (a) collapsibility (b) permeability The die-casting machines are two types– (c) cohesiveness (d) adhesiveness 1. Hot chamber die casting UPRUVNL JE 2016 Shift-I 2. Cold chamber die casting RRB JE [Exam Date : 14-12-2014 (04 Green Paper)] 20. In sand moulding the bottom flask is called– Ans. (b) : The property of sand due to which it evolves (a) Cope (b) Drag a great amount of steam and other gases is called (c) Fillet (d) Riddle permeability. This will be express by permeability RRB JE [Exam Date : 26-08-2015 (Shift-II)] number (Pn). SSC JE 2008 Production Technology 735 YCT Ans : (b) In sand moulding the bottom flask is called 24. The vertical passage for bringing molten metal drag. to mould cavity is called  A moulding flask is one which holds the sand mould (a) gate (b) runner intact. Depending upon the position of the flask in the (c) sprue (d) riser mould structure it is referred by various names such as WBPSC 2016, SSC JE 2012 drag, cope and cheek. Ans. (c) : The vertical passage for bringing molten  It is made up of wood for temporary applications or metal to mould cavity is called sprue. more generally of metal for long-term use. A sprue is the vertical passage through which liquid 21. Sand acquires a predetermined shape under material is introduced into a mould and it is a large pressure and retains the same when pressure is diameter channel through which the material enters the removed. This is due to the property of sand mould. It connects pouring basin to the runner. In many known as : cases it controls flow of material into the mould. It is (a) Plasticity (b) Cohesiveness usually tapered downwards to minimize turbulence and (c) Refractoriness (d) Adhesiveness formation of air bubbles. DMRC 2016 (Paper-I) 25. Aluminium is the best of all the metals for RRB SSE [Exam Date : 01-09-2015 (Shift-III)] making pattern because it is Ans : (a) Sand acquires a predetermined shape under (a) Easy to working (b) Light in weight pressure and retains the same when pressure is (c) Resistant to corrosion (d) All of the above removed. This is due to the property of sand known as WBPSC 2018, 2009 plasticity. Ans. (d) : Aluminium patterns are the good choice for Refractoriness–It is the property of sand to withstand high quality, long lasting production compared to other high temperature of molten metal without fusion. pattern materials. Aluminium is highly resistant to 22. Least shrinkage allowances provided in the corrosion & easy to work (machining). case of following : 26. An expendable pattern is used in : (a) Brass (b) Steel (a) Slush casting (b) Squeeze casting (c) Aluminium (d) Cast Iron (c) Centrifugal casting (d) Investment casting GPSC AMVI (Auto) 24-12-2016 GPSC AMVI (ME) 24-12-2016 GPSC AMVI (ME) 24.12.2016 UPRUVNL JE 2015 Ans. (d) : Shrinkage values for various material- Ans. (d) : An expendable pattern is used in Investment Bismuth – Negligible casting Expendable pattern casting process uses dry White metal – 5 mm/m sand to mould and duplicate the prototype. The geometry of castings is of high precision and there is no Cast iron – 10 mm/m flash burrs, cold shut and the surface finish is close to Aluminium – 13 mm/m the precision casting. Copper – 17 mm/m 27. The property of sand due to which the sand Steel – 20 mm/m grains stick together is called- Brass – 23 mm/m (a) Collapsibility (b) Permeability Zinc – 24 mm/m (c) Cohesiveness (d) Adhesiveness Lead – 26 mm/m NPCIL 07.11.2019 (2.00-4.00 pm) Note- That liquid and solidification shrinkage is HPCL JE 07.11.2019 (Shift-II) maximum for aluminium which required more volume Ans. (c) : The property of sand– of the riser. Cohesiveness– It is the property of sand due to which Solid shrinkage is maximum for brass which requires the sand grains stick together during ramming. It is large size pattern. defined as the strength of the moulding sand. Total shrinkage is maximum for steels. Flow-Ability– Flow-ability is the ability of moulding 23. Metal pattern are used for sand to free flow and fill the recesses and the fine (a) Small castings details in pattern. (b) Large castings Refactoriness– It is the property of sand to withstand (c) Complicated castings high temperature of molten metal without fusion or (d) Large scale production of castings soften. WBPSC 2018, SSC JE 2013 Adhesiveness – It is property of sand due to which the Ans. (d) : A pattern may be defined as a model or sand grains and mould flask stick together. replica of desired casting which when moulded is sand 28. Draft is provided in pattern so that : forms an impression called mould. The mould when (a) It can be easily withdrawn from mould cavity filled with molten metal forms casting after (b) Sand can be filled easily solidification of the poured metal. (c) Compression can be done effectively The quality and accuracy of casting depends upon the (d) Casting can be solidifying easily pattern making. Metal pattern are used for large scale DMRC 2016 (Paper-I) production of castings. ISRO LPSC 11-05-2014 Production Technology 736 YCT Ans : (a) Draft provided in pattern so that it can be Ans. (c) : Skeleton Pattern–When the size of the easily withdrawn from mould cavity without damaging casting is very large, but easy to shape and only a few it. number are to be made. It is uneconomical to make a large solid pattern of that size. In such case, a pattern consisting of a wooden frame and strips is made, called skeleton pattern. Types of patterns– 1. Solid or single piece pattern 2. Two-piece or split pattern 3. Multi-piece pattern 4. Match plate pattern 5. Gated pattern 6. Skeleton pattern o 1 7. Sweep pattern  The average value of draft allowance is    2o 8. Pattern with loose pieces 2 9. Cope and drag pattern Note– Wooden pattern require more taper than metal 10. Follow board pattern pattern. 11. Segmental pattern 29. Upper moulding flask is named as: 32. The purpose of a gate in casting is to : (a) Drag (b) Upper board (a) Deliver molten metal into the mould cavity (c) Check (d) Cope (b) Act as a reservoir for the molten metal DMRC 18-02-2017 (c) Vent out trapped gases RRB JE [Exam Date-14.12.2014 (01 Red paper)] (d) Provide shape to the mould cavity Mizoram PSC 2019 (Paper-I) Ans : (d) Moulds are prepared in a specially ISRO VSSC 07-04-2012 constructed boxes called flasks, which are open at the top and bottom, they are made in two parts, held in Ans : (a) Gating System– The passage-way which alignment by dowel pin. The top parts is called cope serves to deliver the molten metal into the mould cavity is known as gating system. A gating system consists of and lower part as drag. a pouring cup, a down gate or sprue, a runner and an ingate. There are various types of gates such as parting line gates, bottom gates, horn gate, branch gate and top gate.  If the flask is made in three part, the intermediate part is called cheek. 30. Hollow cylindrical bodies like water pipes, gun barrels etc. can be manufactured by– (a) Investment casting (b) Die casting (c) Centrifugal casting (d) Shell moulding MPSC AMVI 2004, 2003 MPSC MVI 2001 33. When pattern is made in three parts, the top part is known as Ans. (c) : Hollow cylindrical bodies like water pipes, (a) Cope (b) Drag gun barrels, large sizes bushes and hollow propellers (c) Cheek (d) Runner shafts can be manufactured by centrifugal casting. WBPSC 2018, 2000  To produce hollow objects in mass production Ans. (a) : When a pattern is made in three parts, the without using the core this technique is used. bottom part is known as drag the top part is known as  In centrifugal casting liquid metal enters the die cope while the middle one is called cheek. under rotation. surface finish of this casting is very  Dowel pin is used for alignment of pattern when it is high and no gating elements are used. made in more than one parts. 31. Skeleton patterns are generally used for- 34. The sand used for making cores is (a) Small castings (b) Non-ferrous castings (a) Loam Sand (b) Green Sand (c) Large castings (d) Hollow castings (c) Oil Sand (d) Pairing Sand NPCIL 07.11.2019 (9.00-11.00 am) VIZAG JET 2017 HPCL JE 07.11.2019 (Shift-I) WBPSC 2000 Production Technology 737 YCT Ans. (c) : Oil sand– A sand used for the preparation of 38. To improve the surface finish of castings, the cores is called oil sand. following additive is used in the moulding sand :  It is sometimes called core sand. It is silica sand (a) Resins (b) Oils mixed with linseed oil or any other oil as binder. (c) Wood flour (d) Sea coal BSSC, WRD JE 2016 Loam sand– A mixture of 50% sand grains and 50% SSC JE 2014 (Morning) clay is called loam sand. It is used for loam moulding or large grey cast-iron casting. Ans. : (d) Sea coal is used to improve the surface finish of casting. 35. A sprue hole is Sea coal is used in moulding sand as a reducing (a) An eccentric hole element to protect it from oxidation. Generally it is (b) An opening in a mould into which the mixed with facing sand by which strength and molten is poured cohesiveness of sand decreases & surface finish (c) An air vent property increases. (d) None of the above 39. Plastic toys are usually produced by using SSC JE 01 March, 2017 (Shift-I) (a) shell moulding (b) green sand moulding GSSB ITI Supervision Inst. (Mech) 18-01-2015 (c) plaster moulding (d) injection moulding Ans. (b) : A sprue is the vertical passage through BSSC WRD JE 2016 which liquid material is introduced into a mould and it SSC JE 2014 (Morning) is a large diameter channel through which the material Ans. : (d) Plastic toys are usually produced by using enters the mould. It connects pouring basin to the injection moulding. runner. Injection Moulding–Injection moulding is the process of making custom plastic parts by injecting molten plastic material at high pressure into a metal mould. Just like the other form of plastic moulding, after the molten plastic is injected in to the mould, the mould is cooled and opened to reveal a solid plastic parts. 40. A casting defect which results in general enlargement of a casting is known as : (a) sand wash (b) swell 36. Uniform sand hardness is obtained throughout (c) blow hole (d) shift the mould by which of the following moulding BSSC WRD JE 2016 machines? SSC JE 2014 (Evening) (a) Diaphragm moulding (b) Stripper plate Ans. : (b) A casting defect which results in general (c) Sand slinger (d) Squeezing enlargement of a casting is known as swell. MRPL Tech. Asst. Trainee 2021 Swell- It is the enlargement of the mould cavity SSC JE 2008 because of the molten metal pressure, which results in Ans. : (a) Diaphragm Moulding–It is used for uniform localized or overall enlargement of the casting. ramming and hardness of the sand. 41. Cast iron and steel pipes are produced by Sand slinger throws sand into mould box rapidly with (a) Centrifugal casting (b) Slush Casting high force/high velocity. They are used to fill large (c) Die Casting (d) Investment Casting flasks and are typically operated automatically. RRB JE [Exam Date-26.08.2015 (Shift-II)] Diaphragm moulding rams the sand in moulding box. WBPSC 2000 37. The main advantage of shell moulding is that : Ans. (a) : It is used in manufacturing cast iron and steel pipes etc. (a) a metallic pattern is used Centrifugal Casting– A casting process in which (b) the moulds are stronger molten metal is poured and allowed to solidify while the (c) thin sections can be easily obtained mould is revolving, is called centrifugal process. The (d) high production rate is possible casting produced under the centrifugal force is called SSC JE 04 March, 2017 (Shift-II) centrifugal casting. SSC JE 2008  This process is used for symmetrical shape product. Ans. : (c) The main advantage of shell moulding is that  Core is not used in this casting method. thin sections can be easily obtained.  Ferrous & non-ferrous metals can be casted by this Some other advantage of shell moulding are – method.  Castings produced by this process are ready for used 42. Plastic bottles are made using with little or no machining required. (a) Blow moulding (b) Injection moulding  Very close tolerances and better surface finish can be (c) Perform moulding (d) Slush casting produced. This is made possible because of the fine UPRVUNL JE 2015 grain of sand used next to the mould cavity. DMRC 20.07.2013 Production Technology 738 YCT  Ans. (a) : Plastic bottles are made using Blow Ans. (d) : Investment casting is a manufacturing moulding. process in which a wax pattern is coated with refractory In blow moulding process, a heated tube of plastic ceramic material. It is also known as hot investment material is situated between the two half of mould, casting, lost wax casting and lost pattern casting. then the mould is closed and air or inert gas is usually Application– blown at a pressure of 200-400 bars which helps the (i) Turbine Blade (2) Gold Ornaments expanding of tube outward to occupy the mould cavity. (3) Medical implants (4) Jet engine parts. 43. If a workshop engineer wants to perform hot 47. Green sand is a mixture of chamber die casting, then which of the (a) 30% sand, 70% clay following alloys will be best suited for the (b) 50% sand, 50% clay mentioned purpose? (c) 70% sand, 30% clay (a) Low Carbon steel (b) Titanium (d) 90% sand, 10% clay (c) Copper (d) Tin TSPSC AE 2015, PSPCL JE 2012 OSSC JE 24.08.2021 Shift-I Ans. (c) : Green sand- 70% sand, 30% clay. Mizoram PSC 2018 (Paper-III) Moulding sand- UPRVUNL JE 2014 (i) Silica – 70-80% (due to silica voids are present) Ans. (d) : Hot chamber process is most suitable for (ii) Clay – 10-20% low melting point alloys like zinc, magnesium, tin and (iii) Water – 2-8% lead etc. (iv) Additives – 1-6%  The cold chamber process is most suitable for high (v) Loam moulding sand - 50% sand & 50% clay melting point alloys of aluminum, copper, brass etc. 48. Directional solidification in castings can be 44. The chief advantage of die casting is : improved by using : (a) possibility of incorporating thick sections in (a) chills and chaplets small castings (b) chills and padding (b) casting of inserts is possible (c) chaplets and padding (c) wide tolerances are possible (d) chills, chaplets and padding. (d) high production rates are possible SSC JE 2015, ESE-1995 SSC JE 04 March, 2017 (Shift-I) Ans. (b) : Directional solidification in casting can be SSC JE 2007 improved by using chills and padding. Ans. : (d) The chief advantage of die casting is high Chills– At a minimum cross - section in the mould production rates are possible. cavity to maximize the heat transfer rate and to provide  In die casting, a permanent mould is used. Generally uniforms & direction solidification metallic objects are low melting point alloys casting is done here. provided known as chills. Advantages of die casting– Padding– At critical cross-section to minimum erosion (i) High production rates and to provide uniform cooling and uniform (ii) Good strength solidification metallic object is used, known as padding. (iii) Intricate shape 49. In solidification of metal during casting (iv) Dimensional precision compensation for solid contraction is : (v) Excellent surface finish. (a) Provided by the oversize pattern 45. Which of the following is not a casting (b) Achieved by properly placed risers process? (c) Obtained by promoting direction (a) Carthias process solidification (b) Extrusion (d) Made by provided chills (c) Semi-centrifuge method UPRUVNL JE 2015, ESE-1999 (d) Slush process Ans. (a) : In solidification of metal during casting SSC JE 02 March, 2017 (Shift-I) compensation for solid contraction is provided by the SSC JE 2009 oversize pattern. Ans. : (b) Extrusion is not a casting process, while carthias process, semicentrifugal, and slush process are casting process.  Extrusion is the process of confining the metal in a closed cavity and then allowing it to flow from only one opening the operation is identical to the squeezing of tooth paste out of a tooth paste tube. 46. Investment casting is also known as (a) hot investment casting (b) lost wax casting (c) lost pattern casting (d) All of these SSC JE 27. 1. 2018 (3.15 pm) MP Sub Engineer 04 April, 2016 (Evening) Production Technology 739 YCT 50. Which one of the following processes produces 54. Ornaments are cast by : a casting when pressure force the molten metal (a) continuous casting (b) slush casting into the mould cavity ? (c) die casting (d) centrifugal casting (a) Shell moulding (b) Investment casting CSL ET 2018 Shift-I (c) Die casting (d) Continuous casting SSC JE 3 March 2017 Shift-I Vizag JET 28.10.2018, ESE-2005 Ans. (b) : Slush casting is a type of permanent mould Ans. (c) : Die casting involves the preparation of casting that is used to produce hollow parts. components by injecting molten metal at high pressure into a metallic die. In slush casting the metal is permitted to remain in the The die casting machines are of two types - mould only untill a shell of the desired thickness has (i) Hot chamber die casting Furnace is integral with formed. The mould is then inverted and the remaining casting machine. liquid is poured out. (ii) Cold chamber die casting Furnace is separated Application–Toys, Decorative items, Statues, Lamp with casting machine. shades, thin section ornaments. 51. Shell moulding can be used for 55. The blades of a gas turbine are made of : (a) producing milling cutters (a) Mild steel (b) making gold ornaments (b) Stainless steel (c) producing heavy and thick walled casting (c) Carbon steel (d) producing thin casting (d) Neimonic (High nickel alloy) HPSSC JE 10.04.2021, ESE-2006 MRPL Tech. Asstt. Trainee 2021 Ans. (d) : Shell moulding– Ans. (d) : Modern turbine blades often use nickel-  The sand is mixed with a thermosetting resin and is based superalloys that incorporate chromium, cobalt, allowed to come in contact with a heated metal rhenium. Aside from alloy improvements, a major pattern (200ºC) breakthrough was the development of directional  It can be used for complex parts. solidification (DS) and single crystal (SC) production  It provide good surface finish. methods.  Materials that can be casted : Cast iron, Al and Cu 56. Match-I with List-II and select the correct alloys. answer using the codes given below the lists:  Very thin section can be cast. List-I List-II  Very small amount of sand is needed. A. Top gate 1. Heavy and larger casting 52. Which of the following is added to aluminium to increase its casting ability ? B. Bottom gate 2. Most widely used (a) Copper (b) Magnesium economical (c) Silicon (d) Lead and Bismuth C. Parting gate 3. Turbulence OSSC JE 24.08.2021 Shift-III D. Step gate 4. Unfavourable temperature JK SSB JE (103) 2014 gradient Ans. (c) : Silicon is added to aluminium to increase its Code: casting ability. A B C D The addition of silicon to aluminium reduces melting (a) 3 4 2 1 temperature and improves fluidity. (b) 1 4 2 3 53. According to Chvorinov's equation, the (c) 3 2 4 1 solidification time of a casting is proportional (d) 1 2 3 4 to: (a) V2 (b) V HPSSC JE 10.04.2021 (c) 1/V (d) 1/V2 Ans. (c) : [Where, V = volume of casting] Top gate Turbulence OSSC JE 24.08.2021 Shift-I, ESE-2006 Bottom gate Most widely used economical Ans. (a) : According to Chvorinov's equation - Parting gate Unfavourable temperature gradient 2 V Step gate Heavy and larger casting The solidification time (ts) = K   A 57. Chaplets are used in ____. 1 (a) welding (b) extrusion So ts  V2 and ts  2 A (c) casting (d) forging Where SSC JE 22-03-2021 Shift-II K solidification facter (s/m2) Ans. (c) : Chaplets are used in casting process which V Volume of casting support cores inside the mould cavity to take care of its A Surface area of casting weight and overcome metals static forces. Production Technology 740 YCT 58. Match List-I with List-II and select the correct 62. The mould walls of a permanent mould have answer using the codes given below the lists: thickness List-I List-II (a) 6 mm to 20 mm (b) 15 mm to 50 mm A. Connecting rod 1. Welding (c) 8 mm to 30 mm (d) 10 mm to 40 mm B. Pressure vessels 2. Extrusion KARNATAKA PSC AE (WRD) 31.07.2021 C. Machine tool beds 3. Forging Ans. (b) : Permanent mould casting is typically used for D. Collapsible tubes 4. Casting high volume production of simple metal parts with Code: uniform wall thickness. The mould walls of permanent mould have thickness in the range of 15 mm to 50 mm. A B C D (a) 2 1 4 3 63. Which of the following acts as reservoir of (b) 3 1 4 2 molten metal and supply it as required to overcome porosity because of shrinkage while (c) 2 4 1 3 solidification? (d) 3 4 1 2 (a) Sprue (b) Riser HPSSC JE 10.04.2021 (c) Pouring basin (d) Runner Ans. (b) : NRL GET 23.09.2021 Shift-I Connecting rod Forging Ans. (b) : Riser is a reservoir of molten metal that feeds Pressure vessels Welding the casting as it solidifies but its main aim not just a Machine tool beds Casting reservoir but to compensate for the below two Collapsible tubes Extrusion shrinkage. 59. The passage way of bringing the molten to the  Liquid shrinkage, the shrinkage when the metal is mould cavity is called as liquid, generally liquid shrinkage is negligible. (a) piping system (b) entry system  Solidification shrinkage, the shrinkage when metal (c) gating system (d) loaming system loose its latent heat during phase change. It may very GPSC AEE (GMC) Class-3 12.09.2021 from 12 to 15%. Ans. (c) : The passage way of bringing the molten 64. ______ Is a type of casting defect which arise metal to the mould cavity is called as gating system. due to improper venting of sand. (a) Cold shuts (b) Swell (c) Shift (d) Blow holes UPRVUNL JE 25.10.2021 Shift-I Ans. (d) : Blowhole :- It is a casting defect. It is arise due to improper venting of sand. Cold shuts :- Cold shuts occur when the mould cavity is not completely filled and incomplete casting results. Shift :- It results in a mismatching of the top and 60. What a pattern is to be withdrawn from the bottom parts of a casting, usually at the parting line. mould, it is first shaken, by striking over it Swell :- It is a casting defect found on vertical surfaces from side to side, so that its surface may be of a casting due to hydrostatic pressure. free of the adjoining sand wall of the mould. That causes the size of the mould cavity 65. The reduction of clay content in the moulding increases a little and a negative allowance is to increases the______. be provided in the pattern to compensate the (a) Green strength (b) Permeability same, is known as: (c) Refractoriness (d) Flowability (a) Draft allowance UPRVUNL JE 25.10.2021 Shift-I (b) Rapping allowance Ans. (b) : The reduction of clay content in the moulding (c) Machining allowance increases the permeability. (d) Shrinkage allowance Permeability is ability of moulding sand which enables NRL GET 23.09.2021 Shift-II trapped gases to escape from mould to produce sound Ans. (b) : casting. 61. Pressures in Bag moulding technique is upto Vh Pn  (a) 20 MPa (b) 1000 MPa PAt (c) 230 MPa (d) 640 MPa Pn Permeability number Karnataka PSC AE(WRD) 31.07.2021 V Volume of air passing through the specimen Ans. (d) : Bag Moulding process – It involves placing a specialized over a plastic workpiece while it is inside h height of standard specimen a mold cavity, and applying vacuum or compressed air p Pressure of the air passing through the specimen pressure around the bag. A cross sectional area of cylindrical specimen  The pressure in bag moulding techniques is 640 MPa. t Time required to pass through the specimen. Production Technology 741 YCT 66. A hot chamber die casting machine melts non- 70. A casting of volume V and the surface area is ferrous alloys which has an uniqueness of cooled in an open-air naturally. The time ______. required for solidification of casting is (a) Melting pot may have any location (a) directly proportional to V/A (b) High temperature and pressure is used (b) inversely proportional to V/A (c) Melting pot is separate from the machine (c) directly proportional to (V/A)2 (d) Melting pot is an integral part of the machine (d) Inversely proportional to (V/A)2 UPRVUNL JE 25.10.2021 Shift-I HPCL Engineer 12.08.2021 Shift-I Ans. (d) : Hot chamber die casting machine:- In a hot chamber die casting machine, the melting pot is an Ans. (c) : Chvorinov's Rules. integral part of machine. The hot chamber die casting 2 V  machine is used for casting Zinc, Tin, Lead and other Total solidification time (ts )  K   low melting alloy.  A Cold chamber die casting machine:- In a cold 2 chamber die casting machine, the melting pot is usually V ts    separate from the machine and the molten metal is A transferred to injection mechanism by ladle. It is used other high melting alloys. Where, V =Volume of mould A= Surface area 67. The cold chamber die casting machine is ideal device for high melting point metals and it K= Solidification factor (sec/m2) has______ 71. Long cast-iron pipes of uniform thickness are (a) Melting pot separate from the machine manufactured by (b) Melting pot as an integral part of the machine (a) centrifugal casting method (c) Low temperature and pressure (b) Green Sand casting method (d) Melting pot may have any location (c) Lost wax method UPRVUNL JE 25.10.2021 Shift-I (d) Die casting method WBPSC 2018 HPCL Engineer 12.08.2021 Shift-I Ans. (a) : Hot chamber die casting machine– In a hot Ans. (a) : Long cast iron pipes of uniform thickness are chamber die casting machine, the melting pot is an manufactured by centrifugal casting method integral part of machine. The hot chamber die casting machine is used for casting Zinc, Tin, Lead and other 72. ______is the traditional method of permanent low melting point alloy. casting process, where the molten metal is not Cold chamber die casting machine– In a cold allowed to completely solidify in the mould. chamber die casting machine, the melting pot is usually (a) Permanent mould casting separate from the machine and the molten metal is (b) Die casting transferred to injection mechanism by ladle. It is used (c) Slush casting other high melting alloys. (d) Centrifugal casting 68. Hot chamber die casting is suitable for: UPRVUNL JE 25.10.2021 Shift-I (a) high melting point alloys Ans. (c) : Slush casting is a traditional method of (b) low melting point alloys permanent mold casting process, where the molten (c) Both low and high melting point alloys metal is not allowed to completely solidify in the mold. (d) heavy ferrous metal only When the desired thickness in obtained, the remaining CPCB Scientist-B 08.09.2021 molten metal in poured out. Ans. (b) : Hot chamber die casting is suitable for low Slush casting method is an effective technique to cast melting point alloys like, Zinc, Tin, Lead etc. Where as hollow items like decorative pieces, components, cold chamber die casting is suitable for high melting point alloys like copper, aluminium etc. ornaments etc. 69. The allowance for the liquid shrinkage is 73. Which of the following is TRUE about "Hot considered in designing casting patterns. The tears"? reduction in the volume of cast metal occurs (a) It is a casting defect during (b) It is a strength parameter (a) Cooling of liquid metal to solid-state (c) It is a hot working process carried out on (b) Rise in volume of a raiser metals (c) Mould cooling (d) It is a type of rusting of metals (d) Due to ramming UPRVUNL JE 25.10.2021 Shift-II HPCL Engineer 12.08.2021 Shift-I Ans. (a) : Hot tears– It is a casting defect. It is an Ans. (a) : For designing of pattern allowance for the liquid shrinkage is considered. The reduction in the internal or external ragged discontinuity in the metal volume of cast metal occurs during cooling of liquid costing resulting form hindered contraction occurring metal to solid state. just after the metal has solidified Production Technology 742 YCT 74. Riser is used in a sand casting to reduce: (a) mould erosion (b) the slag inclusion (c) shrinkage cavities (d) cold shut UPRVUNL JE 25.10.2021 Shift-II Ans. (c) : Riser is used in a sand casting to reduce shrinkage cavities. Drop:- An irregularity shaped projection on the cope 75. A pattern made of wood used to generate surface of a casting is called drop. This is caused by surfaces of revolution in large castings is dropping of sand form the cope or other overhand called: projection in the mould. (a) Cope and drag pattern (b) Match pattern (c) Gated pattern (d) Sweep pattern UPRVUNL JE 24.10.2021, Shift-II Ans. (d) : Sweep pattern:- It used when 2-D pattern used to produce symmetrical 3-D casting e.g. cone, 78. Carbueretters are manufactured by ______ bells of temples. (a) Shell molding (b) Soldering (c) Welding (d) Die casting 76. Which of the following is NOT the main UPRVUNL JE 25.10.2021 Shift-II constituent of Green Sand Mould? Ans. (d) : Carbueretters are manufactured by die (a) Water (b) Clay casting. (c) Sand (d) Chalk 79. Which one of the following material is used for UPRVUNL JE 24.10.2021, Shift-II disposable patterns? Ans. (d) : Green Sand– The sand in its natural or moist (a) Polystyrene (b) Wood state is called green sand. It is also called tempered (c) Rubber (d) Metal sand. It is mixture of silica sand with 20 to 30 percentile UPRVUNL JE 25.10.2021 Shift-II clay having total amount of water from 6 to 10 percent. The mould prepare with sand are green sand mould. Ans. (a) : Polystyrene is used for disposable patterns. 80. ____ is used to improve the directional 77. The defect in Casting, in which a scar covered solidification for difficult casting geometries. by thin layers of metal is produced, is known (a) Step gate (b) Chill as: (c) Runner extension (d) Parting gate (a) Gas holes (b) Porosity UPRVUNL JE 25.10.2021 Shift-II (c) Blow (d) Blister Ans. (b) : Chill is used to improve the directional UPRVUNL JE 24.10.2021, Shift-II solidification for difficult casting geometries. Ans. (d) : Casting defects 81. Which of the following pattern is used to Gas holes when the evolved gases or dissolved gases in produce a large number of castings ? the molten metal are not able to leave the man of molten (a) Loose piece pattern (b) Split pattern metal as it wildfires and get trapped within the casting (c) Gated pattern (d) Match plate pattern GPSC AMVI 2020 Ans. (c) : Gated pattern :-  In this the pattern are usually made of metals.  In this mould-cavity moulds are produced & the sections connecting different pattern serves as gate Scar– A shallow blow, usually found on a flat casting and runner. This facilitates filling the mould in better manner. surface is referred to as scar.  Used for small casting such as corner bracket. 82. Fine grain size during the solidification of a metal is achieved by (a) lower nucleation rate Blister–This is a scar covered by a thin layer. (b) higher nucleation rate with lower growth rate (c) higher nucleation rate with higher growth rate (d) lower growth rate GPSC (Mech) 21.07.2019 Ans. (b) :  During the solidification of pure molten Pin hole:- When hot metal comes into the contact of metal, the grains in the casting near the mould wall are moisture H2O is disintegrates into H2 and O2 As H2 fine and randomly oriented because the rate of comes out slowly it produces large number of fine holes solidification is high at the surface of mould during over the casted part. solidification. Production Technology 743 YCT The grain size in the product phase depends on the 87. The cavity, made in a suitable refractory relative rates of nucleation and growth. material that can withstand the high Each nucleating particle becomes a grain in final temperature, into which molten metal can be product. poured is known as So a high nucleation rates means a larger number of (a) Mould (b) Pattern grains. (c) Core (d) None of the options Also when this is combined with a low growth rate, GPSC (Mech) 21.07.2019 more time available for further nucleation to take place Ans. (a) : The cavity, made in a suitable refractory and parent phase that lies between slowly growing material that can withstand the high temperature, into particles. which molten metal can be poured is known as mould. So combination of high nucleation and a slow growth  The moulding material commonly used in foundry rate yields a fine grain size. practice are moulding sand, sand binders and sand 83. Shrinkage and weld stress in casting is additives. responsible for which welding defect ? 88. Which pattern material transforms into (a) Incomplete fusion (b) Rat tail gaseous state, leaving negligible residue and the (c) Shrinkage void (d) Lamellar tearing space occupied by the pattern filled, when the DSSSB JE 16-11-2019 (12.30-2.30) molten metal is poured into the mould, Ans. (d) : Shrinkage and weld stress in casting is (a) Wood (b) Metal responsible for Lamellar tearing welding defect. (c) Plasticity (d) Polystyrene  Lamellar tearing is caused mainly by sulfurous GPSC (Mech) 21.07.2019 inclusions in the material. Other causes include an Ans. (d) : The pattern which is made of polystyrene excess of hydrogen in the alloy. This defect can be material transforms into gaseous state, leaving mitigated by keeping the amount of sulphur in the negligible residue and the space occupied by the pattern steel alloy below 0.005%. filled, when the molten metal is poured into the mould. 84. ______ enhances the directional solidification  This type pattern is called investment pattern. of complex casting geometries. 89. The extra material added to the certain parts of (a) Runner extension (b) Bottom gate the casting to enable their machining or (c) step gate (d) Chill finishing to the required size, accuracy and HPCL JE 20-04-2019 surface finish is known as Ans. (d) : Chill enhances the directional solidification (a) Shrinkage allowance of complex casting geometries. It is a metallic objects, (b) Machining allowance which are placed in the mould to increase the cooling (c) Draft allowance rate of casting to provide uniform cooling rate. (d) None of the options Chill & padding both are used for directional GPSC (Mech) 21.07.2019 solidification. Ans. (b) : The extra material added to the certain parts 85. When gases are entrapped on the surface of of the casting to enable their machining or finishing to casting due to solidification of metal then oval the required size, accuracy and surface finish is known cavity is formed. This type of casting defect is as machining or finishing allowance. known as : 90. In a casting process the height of the molten (a) Cold shut (b) Swell metal from the ingate to the pattern is 0.5 m, (c) Blowholes (d) Drop then the velocity of flow of the molten metal DSSSB JE 16-11-2019 (4.30-6.30) through the ingate is......... (Assume Ans. (c) : When gases are entrapped on the surface of acceleration due to gravity as 10 m/s2) casting due to solidification of metal then oval cavity is (a) 10 m/s (b) 10 m / s formed. This type of casting defect is known as blowholes. (c) 0.5 m/s (d) 5 m / s Blowhole is an excessively smooth depressions on the ISRO MCF 23-06-2019 outer surface of a casting. Ans. (b) : Given that– 86. Which of the following material can be used for Height of molten metal from the ingate to the pattern is making patterns ? (h) = 0.5 m (a) Aluminium (b) Wax Gravity acceleration (g) = 10 m/s2 (c) Lead (d) All of these Flow of molten metal V = ? Mizoram PSC 2019 (Paper-1)  We know that– Ans. (d) : A pattern may be defined as a model or V  2gh replica of desired casting. The mould when filled with molten metal forms casting after solidification of the  2g  0.5  2  10  0.5 poured metal. The pattern may be made of wood, metal, plaster, plastic and wax. V  10 m / s , V  10 m / s Production Technology 744 YCT 91. Which of the following is true about riser? (c) moistening the sand around the edge before (i) It permits the molten metal to rise above the removing pattern highest point in the casting (d) reinforcement of sand in the top part of the (ii) Filling up of mould cavity can be visually moulding box checked from it WBPSC 2018 (iii) The casting solidifies directionally towards Ans. (c) : Swab–Swab is a hemp fiber brush used for the riser moistening the edges of sand mould. Which are in (a) (i) and (ii) (b) (i) and (iii) contact with the pattern surface, before withdrawing the (c) only (ii) (d) (i), (ii) and (iii) pattern. ISRO MCF 23-06-2019 It is also used for coating the liquid blacking on the mould face in dry sand moulds. Ans. (d) : A riser also known as a feeder, is a reservoir built into a metal casting mould to prevent cavities due 95. The casting method adopted for ornaments and to shrinkage. Most metals are less dense as liquid as a toys of non- ferrous alloys, is solid so casting shrink upon cooling, which can leave (a) permanent mould casting avoid at last point to solidity. Risers prevent this by (b) slush casting providing molten metal to the casting as it solidifies, so (c) die casting that cavity forms in the riser and not the casting. (d) centrifugal casting Risers are not effective on materials that have a large WBPSC 2018 freezing range, because directional solidification is not Ans. (b) : Slush casting is a method of casting that uses possible. They are also not needed for casting process permanent mould to produce thin and hollow casting that utilized pressure to fill the mould cavity. without using core. It is used for casting of low melting Types of Risers– point Non-ferrous materials. Decorative items, Tin (i) Top riser ornament, Toys are also made by this method. (ii) Blind riser 96. In a hot chamber die casting machine (iii) Internal riser (a) melting pot is separate from the machine. 92. Which one of the following casting processes (b) melting pot is an integral part of the machine. produces the products with better surface (c) melting pot may have any location. finish? (d) high temperature and pressure is used. (a) Sand casting (b) Hot die casting WBPSC 2018 (c) Investment casting (d) Cold die casting Ans. (b) : In a hot chamber die casting machine melting ISRO MCF 23-06-2019 pot is an integral part of the machine. Molten metal is Ans. (c) : Investment casting also known as precision forced through the cavity of a pre shaped mould using casting is a manufacturing process in which a wax pressure. The defining characteristic of hot-chamber die pattern is coated with a refractory ceramic material. casting is that metal is heated inside the casting machine Once the ceramic material is hardened its internal rather than a separate machine or furnace. geometry takes the shape of the casting. The wax is  Low melting point melted out and molten metal is poured into the cavity  Lead, Tin, Zinc only where the wax pattern was.  Aluminium is not used because of its sticking The pattern for this process may also be made from tendency. plastic. 97. Sagging of thin pattern due to ramming can be It used for casting of complex shaped object close overcome by constructing a supporting block dimension and perfect accuracy. which may fit inside the pattern to serve as a 93. In a gating system, the ratio 1 : 2 : 4 represents: support during ramming such a pattern is (a) Sprue base area : runner area : ingate area called (a) Match plate pattern (b) Pouring basin area : ingate area : runner area (b) Follow board pattern (c) Spue base area : ingate area : casting area (c) Built up pattern (d) Runner area : ingate area : casting area (d) Lagged up pattern Mizoram PSC 2018 (Paper-3) ISRO LPSC 04-03-2018 Ans. (a) : In a gating system, the ratio 1 : 2: 4 Ans : (b) Follow Board Pattern–This pattern is used represents Sprue base area : runner area : Ingate area : for those castings where there are a few portions which  For non - pressurized gating system are structurally weak & if not supported correctly are Spure : Runner : Ingate = 1 : 4 : 4 possible to break under force of ramming. Therefore  For pressurized gating system bottom board is adapted as a follow board to intimately fit in the contour of weak pattern and thus support it Sprue : Runner : Ingate = 2 : 2 : 1 during the ramming. 94. Swab is used for 98. The casting defect misrun occurs when: (a) smoothing and cleaning out depressions in the (a) Liquid metal is not properly poured into the mould down sprue (b) cleaning the moulding sand (b) Metal solidifies before filling the cavity Production Technology 745 YCT  (c) Micro porosity occurs in the casting Ans. (d) : For the production of quality part pressure (d) Globules of metal become entrapped in the die casting is normally employed, because it provides casting very good surface finish and dimensional accuracy. In NPCIL 03.06.2018 pressure die casting, molten metal is forced upward by Ans : (b) Casting Defect–Casting defect create a gas pressure into a metal mould. The pressure is deficiency or imperfection to quality specifications of maintained until initial molten metal has solidified in metal casting some casting defects are– the mould. (i) Misrun–Due to insufficient fluidity and pouring 102. Which of the following is NOT a casting temperature the liquid metal getting solidify before defect? reaching the cavity. (a) Tungsten Inclusion (b) Inclusions (ii) Shrinkage Cavity–Due to improper riser design. (c) Shrinkage cavities (d) Cold shut (iii) Cold Shuts–Two streams of metal will not fuse CSEB AE 2018 properly. (iv) Hot Tears/Cracks–Cracks in casting due to Ans. (a) : casting defects– porosity, Blow holes, gas shrinkage stress. holes, scar, blister, drops, Inclusion, scab etc. (v) Blow Holes & Open Blows–Gas defeats which is 103. Pattern from the mould is drawn by: formed at surface & inside. (a) Stripper – Plate machine (vi) Drop and Dirt–Due to improper reaming. (b) Squeezing machine (vii) Scab–Due to improper reaming form a projection (c) Sand slinger machine on the surface. (d) jolt machine (viii) Mould Shift–Due to improper positioning of cope CSEB AE 2018 box on the drag box. (ix) Pin Hole Porosity–Small size gas holes which are Ans. (a) : Pattern from the mould is drawn by– formed due to H2. Stripper-plate machine. 99.............are casting defects caused by improper 104. The section of casting set-up which traps the shrinkage/hindered contraction. impurities in process is called____. (a) Hot tears (b) Swell (a) Runner (b) Sprue (c) Shifts (d) Fins (c) Skim Bob (d) Riser ISRO IPRC 21-04-2018 CSEB AE 2018 Ans. (a) : Hot tears are casting defects caused by Ans. (c) : The section of casting set-up which traps the improper shrinkage/hindered contraction. Defects impurities in process is called skim bob. arises in casting. 105. Which of the following is usually NOT a (i) Blow holes (ii) Drop function of a riser in casting? (iii) Pin hole (iv) Scale (v) Hot tears (vi) Swell (a) Enabling smooth entry of molten metal (vii) Mould shift (viii) Fins (b) Enabling escape of gases 1. Hot Tears– This appear as cracks in a cast (c) Indication of complete filling of the mould materials. The reason for this is more sand piles (d) Prevention of cavities due to shrinkage and metal cooling is non uniform. CSEB JE 2018 2. Swell–Due to the pressure of molten metal the Ans. (a) : A riser of leader head in a vertical passage normal cavity of the mould increases at a made in the cope to store the liquid metal and supply particular place. Casting also increases as a result. the same to the casting as it solidifies. Store sufficient This defects comes due to not properly ramming liquid metal and supply the same to the casting it or very fast metal pours. solidifies there by avoiding volumetric shrinkage of the 100. Graphite Moulds are generally used for casting. continuous casting method because 106. Which of the following is also known as the (a) the metals wet the mould slightly Lost Wax process? (b) only a small film of lubricating oil is required (c) they are self-lubricating (a) Sand casting (d) they are comparatively cheaper (b) Evaporative pattern casting SSC JE 24. 1. 2018 (10.15 am) (c) Investment casting Ans. (c) Graphite mould is useful for continuous casting (d) Vacuum sealed casting process because they are self-lubricating. In continuous CSEB JE 2018 casting process the pouring and solidification process Ans. (c) : Investment Casting – In this, mould is goes non stop with the casted product being prepared an expandable pattern (wax pattern). It is used continuously drawn from the open end of mould. for making jewelry, surgical equipment etc. 101. For the production of quality part the 107. Which of the following is used to make hollow following casting method is normally employed cavities in casting? (a) centrifugal casting (b) continuous casting (a) Sprue (b) Core (c) green sand casting (d) pressure die casting (c) Gate (d) Pattern SSC JE 27. 1. 2018 (3.15 pm) DMRC 18-02-2017 Production Technology 746 YCT Ans : (b) Core is used to make hollow cavities in 112. Facing sand used in foundry work comprises of. casting. (a) aluminal, silica and clay  The actual entry point through which molten metal (b) silica and clay enters the mould cavity, is called gate. (c) silica and alumina  Sprue is a passage through which the molten metal (d) clay and alumina from the pouring basin reaches the mould cavity. SSC JE 3 March 2017 Shift-I 108. Metallic supports kept inside the mould cavity Ans. (b) Facing Sand- Facing sand is the sand which to support the cores are named: covers the pattern all around it. The remaining box is (a) Chaplets (b) Jammers filled with ordinary floor sand. (c) Grippers (d) Gutters  It is made of silica sand and clay without the DMRC 18-02-2017 addition of any used sand. Ans : (a) Metallic supports kept inside the mould cavity  Facing sand forms the face of the mould and comes to support the cores are called chaplets.  The metal that needs to be casted uses the same in direct contact with the molten metal when it is material chaplet. poured.  Chills and padding are used for directional  High strength and refractoriness are required for this solidification. It is also made of casting material. sand Note–If some embossed part is formed in the pattern to 113. The mould for casting ferrous material in support the core in the mould, it is called core print. continuous casting process is made of_____. 109. Colour code for part to be machined for A. Low carbon steel wooden patterns is represented by following B. Medium carbon steel colour : C. High carbon steel (a) Red or Orange (b) Yellow D. Copper (c) Black on core prints (d) Green (a) Only A (b) Only B MPSC AMVI 2017 (c) Only D (d) None of these Ans. (a) : Colour Code for part to be machined for wooden SSC JE 3 March 2017 Shift-I patterns is represented by Red or Orange colour, Ans. (d) Continuous casting–There is no need to make  The surface to be left unmachined are painted with block colour. mould for this type of casting. In this the molten metal poured between the two dies and they are continuously  The core prints and seats for loose core prints are painted with yellow colour. casted due to gravity.  The seats for loose pieces are marked with red strips  This process is called continuous casting process. on yellow base.  This method is used for casting mostly non-ferrous 110. Gravity die casting is metals. (a) A metal casting process where metal is  Circular or square section of rodes. Pipes tube etc. forced under pressure against gravity. 114. For mounting several patterns at a time, which (b) A permanent mould casting where metal of the following type of pattern is used ? enters the mould under gravity. (a) combined pattern (b) loose, piece pattern (c) A semi-permanent mould casting where metal gravity cores are used (c) sweep pattern (d) match plate pattern (d) Used for producing complicated shapes with SSC JE 4 March 2017 Shift-I low cast die. Ans. (d) For mounting several patterns at a time match Karnataka PSC JE 09-09-2017 plate pattern is used. Ans. (b) : Gravity die casting is A permanent mould  Pattern are made in two pieces one piece mounted on casting where metal enters the mould under gravity. one side and the other on other side of plate called  Gravity Die casting is a permanent mould casting match plate. process, where the molten metal is poured from a  Plate may carry one or more group of pattern vessel or laddle into the mould. mounted on match plate.  The mould cavity fills with no force other than gravity.  Along with pattern gates and runners are also 111. Strength and permeability of served sand are attached. related to :  Generally used for small castings such as piston rings (a) grain size (b) clay–content (c) hardness (d) moisture content of I.C. engine and rotor hub. SSC JE 4 March 2017 Shift-II 115. Casting process is preferred for parts having Ans. (d) Strength and permeability of served sand are......... related to moisture content. (a) a few details (b) many details Porosity or permeability–Due to this property of sand (c) no details (d) non–symmetrical shape air & gasses passes throught the sand from the mould. SSC JE 4 March 2017 Shift-I Production Technology 747 YCT Ans. (b) Casting process is preferred for part having Ans. (c) : Sprue–It is a passage through which liquid many details to create intricate solid shapes. material is introduced into a mould cavity in many cases  Casting process is one of the earliest metal shaping it controls the flow of metal into mould cavity. technique known to human being  It means pouring molten metal into a refractory mould cavity and allow it to solidify.  The solidified object is taken out from the mould either by breaking or taking the mould apart.  The solidified object is called casting and the technique followed in method is known as casting process. 116. For steel castings, the following type of sand is 120. Green sand mould indicates that : better....... (a) Polymeric mould has been cured (a) fine–grain (b) Mould has been totally dried (b) coarser–gain (c) Mould is green in colour (c) medium grain (d) Mould contains moisture (d) fine–grain, coarser-gain and medium grain all GPSC AMVI (ME) 24-12-2016 are equally good Ans. (d) : Green sand mould is a mould that is formed SSC JE 1 March 2017 Shift-I by using green sand that contain moisture. This sand is Ans. (b) For steel casting coarse, grain type sand is used a wet condition it is mixture of silica sand with 15 better. In this type sand, porosity and permeability – 25% clay and 6-8% of water. The sand undergoes property is high. milling process in which various clay and chemical 117. The hot Chamber die casting method is used to additives are blended together with sand. cast _____. 121. What is the name of the process where a (a) Brass permanent mould is rotated continuously about (b) Both brass and Aluminium its axis at high speeds as the molten metal is (c) aluminium poured into it ? (d) alloys of lead, tin and zinc (a) Round robin casting SSC JE 3 March 2017 Shift-I (b) Circular axis casting Ans. (d) The hot chamber die casting method is used (c) Rotor-casting or Centrifugal casting to cast the alloy of lead, tin and zinc into the mould. 1. For mass production (d) None of these 2. Perfect and smooth surface KPCL JE 2016 3. For nonferrous casting Ans. (c) : In centrifugal or rotor-casting process, the 118. While casting, which of the following shrinkage mould is permanent and it is rotate about its axis at high need to taken considered ? speed (300 to 3000 rpm) as the mould metal is poured. (a) Liquid shrinkage (b) Solid shrinkage The centrifugal forced acting on the mould help in (c) Both (a) and (b) (d) None of the above feeding and positioning the metal in the mould. KPCL JE 2016 122. Ornamental objects, statues, toys etc. are cast Ans. (c) : While casting, liquid and solid shrinkage by : need to taken considered. (a) Die casting (b) Continuous casting  Liquid shrinkage is the contraction that occurs as the (c) Centrifugal casting (d) Slush casting alloy cools but remains in its liquid state. GPSC AMVI (ME) 24-12-2016  Solid shrinkage is the continued shrinkage that Ans. (d) : Ornamental objects statue toys etc. are cast occurs as the solid metal casting cools to ambient by slush casting. temperature in its solid state. Slush casting is a variant of Permanent moulding 119. What is a sprue ? casting to create a hollow casting or hollow cast. In the (a) It is the cavity created to facilitate quick process the material is pored into the mould and cooling of liquid material in a mould allowed to cool until a shell of material forms in the (b) It is the cavity created inside the mould for mould. smooth flow of liquid metal 123. The molten metal is poured from the pouring (c) It is the passage through which liquid material basin to the gate with the help of a : is introduced into a mould (a) Riser (b) Sprue (d) None of these (c) Runner (d) Core KPCL JE 2016 GPSC 09-10-2016 Production Technology 748 YCT Ans. (b) The vertical passage for bringing molten metal Ans. (c) Sweep pattern is used for moulding parts to mould cavity is called sprue. having uniform symmetrical shape. A sprue is the vertical passage through which liquid  A sweep is a section or board (wooden) of proper material is introduced into a mould and it is a large contour that is rotated about one edge to shape mould diameter channel through which the material enters the cavities having shapes of rotational symmetry. mould. It connects pouring basin the to the runner. In  This type of pattern is used when a casting of large many cases it controls flow of material into the mould. size is to be produced in short time. It is usually tapered downwards to minimize turbulence  They are used to make large and circular casting in and formation of air bubbles. loam moulding. 124. Blow moulding process to produce such as