120 + Interview Questions in Molding And Core Sands in Casting-Forming-Welding I Page 1 InterviewSolution

1.	Which of the following components of soil are acts as chemical sponges in the soil?(a) Clay minerals(b) Silica(c) Sodium(d) PotassiumThis question was posed to me in an online quiz.This intriguing question originated from Fire Clays, Illite and Kaolinite topic in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct answer is (a) Clay minerals The best I can explain: Clay minerals are quite STABLE and are an important part of the SOIL. Clay minerals are ALSO called as chemical sponges which basically HOLD water content and dissolved nutrients from other mineral particles. This results due to the presence of unstable electric charges on the surface of clay particles, in which opposite charges attract to each other.

Discussion

2.	Good friability is one of the properties of core sand.(a) True(b) FalseThis question was addressed to me in a national level competition.My question comes from Indian Sand and core sand topic in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» CORRECT option is (a) True For EXPLANATION: Good friability is one of the properties of the CORE SAND so that the core falls AWAY when it is to be removed from castings.

Discussion

3.	In which of the following bonding theory, water molecules break down to form H+ and OH- ions?(a) Electrostatic bonding theory(b) Hot strength theory(c) Surface tension theory(d) Block and wedge theoryThe question was asked by my college professor while I was bunking the class.The above asked question is from Bonding Theory in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» CORRECT OPTION is (a) Electrostatic bonding theory Explanation: In electrostatic bonding theory, water is MIXED in clay and sand grains, these water molecules then break into H^+ IONS and OH^– ions.

Discussion

4.	Which of the following sand is freely available?(a) Silica sand(b) Zircon(c) Olivine(d) DolomiteI have been asked this question in an international level competition.My doubt stems from Refractory Sands in section Molding and Core Sands of Casting-Forming-Welding I
Answer» Right choice is (a) Silica sand To explain I would SAY: Silica sand has this as ONE of its advantages, that it is AVAILABLE without any DIFFICULTY in abundance. Hence, the COST of silica sand is also low.

Discussion

5.	Which of the following is the most porous sand?(a) Silica sand(b) Zircon(c) Olivine(d) DolomiteI had been asked this question in an international level competition.The above asked question is from Refractory Sands topic in division Molding and Core Sands of Casting-Forming-Welding I
Answer» Right answer is (a) Silica sand For explanation I would SAY: Even when the silica sand are packed as MOULD cavity, they show enough POROSITY and permeability, and hence are POROUS sands.

Discussion

6.	Illite has a softening point of about 4500°F.(a) True(b) FalseThis question was posed to me in semester exam.The doubt is from Molding Sands Binders in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» Right answer is (b) False The EXPLANATION: ILLITE is a decomposition product due to weathering, and is FOUND in natural moulding sands. It has its softening temperature at about 2500°F.

Discussion

7.	What is the breadth size range of a clay particle?(a) 0.01-1 micrometres(b) 0.02-2 micrometres(c) 0.03-3 micrometres(d) 0.04-4 micrometresThe question was asked in class test.This is a very interesting question from Molding Sands Binders topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct ANSWER is (a) 0.01-1 micrometres For explanation I would say: The particles of clay are very small and need HIGH precision MICROSCOPES to determine its size. Clay particles in their breadth have a particle size range in between 0.01 micrometres to 1 micrometres.

Discussion

8.	On increasing the binder content, what in the moulding sand gets reduced?(a) Hardenability(b) Strength(c) Permeability(d) BrittlenessI got this question in an online quiz.My query is from Molding Sands Binders in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» Right OPTION is (c) Permeability Easiest explanation: On increasing the BINDER content, the hardenability does not get affected. The strength and the BRITTLENESS to do not change, but on ADDITION of too much of binder in the moulding sand, the permeability of the moulding sand GETS reduced.

Discussion

9.	The figure below shows which foundry sand grain shape?(a) Round(b) Sub angular(c) Angular(d) CompoundThe question was posed to me in class test.Enquiry is from Molding Sands in division Molding and Core Sands of Casting-Forming-Welding I
Answer» CORRECT OPTION is (d) Compound The BEST EXPLANATION: NONE.

Discussion

10.	The figure below shows which foundry sand grain shape?(a) Round(b) Sub angular(c) Angular(d) CompoundThe question was asked during an internship interview.The origin of the question is Molding Sands in section Molding and Core Sands of Casting-Forming-Welding I
Answer» CORRECT answer is (C) ANGULAR Explanation: FOUNDRY sand grain is categorised into four types which are, ROUND type, sub-angular type, angular type and compound type. This figure here, depicts angular sand grain.

Discussion

11.	Which sand is used for casting cast irons and non-ferrous metals?(a) Loam Sand(b) Natural Sand(c) Synthetic Sand(d) Refractory sand grainThis question was addressed to me during an interview for a job.My question comes from Molding Sands in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct OPTION is (B) Natural Sand The EXPLANATION: For casting iron and non-ferrous metals, natural sand is used. The loam sand, the synthetic sand and the REFRACTORY grain sand do not PLAY any role in casting them.

Discussion

12.	In synthetic sands of aluminium alloys, what is the bentonite percentage composition?(a) 2-5%(b) 3-5%(c) 4-5%(d) 5-6%The question was asked in final exam.My question comes from Molding Sand Mixtures for Casting in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» The CORRECT CHOICE is (c) 4-5% The explanation is: In synthetic SANDS of aluminium alloys, the bentonite percentage composition is calculated to be 4-5%. Whereas, in the case of green sands, the bentonite percentage is recorded to be around 3.5%.

Discussion

13.	In green sand moulding of steel casting, what is the moisture percentage composition?(a) 2-3%(b) 3-4%(c) 4-5%(d) 5-6%I have been asked this question in a job interview.The above asked question is from Molding Sand Mixtures for Casting topic in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct answer is (d) 5-6% To explain: In dry sand MOULDINGS of STEEL CASTINGS, the moisture percentage composition is calculated to be 5-6%. In GREEN sands, the moisture content is relatively LOWER than dry sands. It is around 3% to 4%.

Discussion

14.	What is the amount of sea coal needed in cast irons for small casting moulding sands?(a) 1%(b) 2%(c) 3%(d) 4%I got this question in unit test.Query is from Bonding Theory in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct ANSWER is (a) 1% Easiest EXPLANATION: In bonding of substances, an extremely small quantity of sea coal is also NEEDED. Sea coal is used for SURFACE appearance improvement. It is used about 1% in cast iron MOULDING sands for small castings.

Discussion

15.	Which of the following properties must a material possess to be used in mold making?(a) High refractoriness(b) Chemical and thermal stability(c) High permeability(d) All of the mentionedThe question was posed to me by my school teacher while I was bunking the class.The question is from Mold Materials topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» CORRECT OPTION is (d) All of the mentioned Explanation: A MATERIAL MUST have all of the above PROPERTIES so as to be a good mold making material.

Discussion

16.	In dry sand moulding of steel casting, what is the bentonite percentage composition?(a) 1%(b) 2%(c) 4%(d) 5%This question was addressed to me in a job interview.My doubt is from Molding Sand Mixtures for Casting in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» The CORRECT choice is (d) 5% For explanation: In dry sand MOULDINGS of steel castings, the BENTONITE PERCENTAGE COMPOSITION is calculated to be 5% and in green sand, the bentonite percentage is calculated to be 3.5%.

Discussion

17.	Which of the following members of clay minerals is formed by the decompositions of micas?(a) Chlorite(b) Illite(c) Kaolinite(d) VermiculiteI got this question in semester exam.My question is taken from Fire Clays, Illite and Kaolinite topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct CHOICE is (d) Vermiculite Easiest EXPLANATION: Vermiculite is a very important and essential member of clay MINERALS which is normally formed by the decompositions of micas and occurs as completely large crystals of mica like appearance. It has a layer structure which basically consists of water particles and EXCHANGEABLE cations which are mainly magnesium IONS.

Discussion

18.	Phosphorus is added to steel mold for which of the following reason?(a) It increases strength and hardness of steel(b) It increases refractoriness of steel(c) It increases porosity of steel(d) It increases finishing of steelThe question was posed to me in my homework.Asked question is from Mold Materials topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct CHOICE is (a) It increases strength and HARDNESS of steel Best explanation: PHOSPHORUS has the ABILITY to INCREASE strength and hardness of steel material when added to it in the right compostion (2-4%).

Discussion

19.	What is the amount of green permeability in light to medium size malleable iron castings?(a) 34 cc/min(b) 44 cc/min(c) 54 cc/min(d) 64 cc/minThe question was asked during an interview.My query is from Preparation of Core Mix topic in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct option is (b) 44 cc/min The best explanation: The RATE of green permeability is quite a decent ONE. The AMOUNT of green permeability in LIGHT to medium SIZE malleable iron castings is 44 cc/min.

Discussion

20.	It becomes easier to read the bottom part of the meniscus when the hydrometer is in a soil suspension.(a) True(b) FalseThe question was posed to me in final exam.The question is from Grain Size and Shape topic in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct choice is (B) False For EXPLANATION: It is impossible to read the BOTTOM part of the meniscus when the hydrometer is in a soil suspension. In the hydrometer test, it is very necessary or essential to form a graph or table that gives a COMPOSITE CORRECTION as a function of temperature for the present of dispersing agent in the hydrometer.

Discussion

21.	Which refractory sand has the best moulding material?(a) Silica sand(b) Magnesite(c) Zircon(d) OlivineI have been asked this question in quiz.I want to ask this question from Refractory Sands topic in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct answer is (a) SILICA sand Explanation: Silica SANDS are considered to be having the BEST moulding material. It has its occurrence in a VARIETY of crystalline MODIFICATIONS.

Discussion

22.	Which of the following is not a defect if permeability is not enough?(a) Brittleness(b) Gas holes(c) Mould blast(d) Surface blowsThe question was posed to me in examination.The above asked question is from Properties of Molding Sands topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» Right answer is (a) Brittleness The best I can explain: If the permeability or the porosity is LESS or the permeability is FOUND to be INADEQUATE or the porosity is found to be absent, then brittleness is not the defect it has, but it may have, gas holes or mould blasts or surface BLOWS.

Discussion

23.	Parting sand is a type of moulding sand.(a) True(b) FalseI had been asked this question during an interview for a job.The doubt is from Properties of Molding Sands in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct option is (a) True For explanation: PARTING sand is ONE of the many types of MOULDING sand which CONTAINS silica, sand and BURNT sand.

Discussion

24.	Hot strength is seen at what temperature?(a) Above 212°F(b) Above 312°F(c) Above 412°F(d) Above 512°FI got this question by my college professor while I was bunking the class.This interesting question is from Properties of Molding Sands in division Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct answer is (a) Above 212°F Explanation: Hot STRENGTH basically is the strength of the sand which is present inside the MOULD CAVITY. It is OBSERVED that, the hot strength of any material is at 212°F or above it.

Discussion

25.	What is the softening point of western montmorillonite?(a) 800°F – 1150°F(b) 1200°F – 1650°F(c) 1750°F – 2100°F(d) 2100°F – 2450°FThis question was addressed to me in semester exam.This intriguing question comes from Molding Sands Binders in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct answer is (d) 2100°F – 2450°F Explanation: Bentonite is classified into 2 types, namely, Sodium MONTMORILLONITE and Calcium montmorillonite. WESTERN bentonite also CALLED as Sodium montmorillonite is KNOWN to have its softening POINT in the range of 2100°F – 2450°F.

Discussion

26.	The famous iron pillar located near Qutab Minar in New Delhi is made up of which material?(a) Stainless steel(b) Malleable iron(c) Mild steel(d) Wrought ironThe question was asked during an online interview.I would like to ask this question from Mold Materials in division Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct CHOICE is (B) Malleable iron Easiest explanation: Malleable iron is a raw KIND of type of iron which was used in the MAKING of Iron pillar.

Discussion

27.	High refractoriness of a material refers to its __________(a) Slipperyness of the material(b) Chemical strength towards other material(c) Strength to withstand at high temperature(d) Ability to get dissolved in molten metalI had been asked this question during an online exam.This question is from Mold Materials topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct option is (c) Strength to withstand at high temperature To explain: Refractoriness is the resistance to self deformation at high working TEMPERATURES. A material must POSSESS such PROPERTY in order to withstand the temperature of molten metal during CASTING.

Discussion

28.	For bonding action of clays, what is the amount of water needed?(a) 1.5%-8%(b) 3.5%-11%(c) 4.5%-12%(d) 5.5%-13%The question was asked during an internship interview.This key question is from Bonding Theory topic in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» CORRECT option is (a) 1.5%-8% EASIEST explanation: For the bonding ACTION of the clays, water is needed, which ACTIVATES the sand and clay-sand mixture. The amount needed for this is 1.5% to 8%.

Discussion

29.	What is the green compression strength of light to medium size malleable iron castings?(a) 0.05 kg/cm^2(b) 0.06 kg/cm^2(c) 0.07 kg/cm^2(d) 0.08 kg/cm^2This question was posed to me by my college director while I was bunking the class.The query is from Preparation of Core Mix in division Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct choice is (d) 0.08 kg/cm^2 Easiest EXPLANATION: The GREEN compression strength of light to medium size malleable iron casts is 0.08 kg/cm^2, whereas the dry compression strength of a core sand mixture is found to be 70 kg/cm^2.

Discussion

30.	Which of the following is not a core sand property?(a) Dry strength(b) Hardness(c) Low collapsibility(d) Good PermeabilityThe question was posed to me during a job interview.This intriguing question comes from Indian Sand and core sand topic in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» RIGHT answer is (c) Low collapsibility The best explanation: Dry strength, hardness and a GOOD amount of permeability are a few properties of CORE SAND. Low collapsibility is not any of the property of core sands, in fact, core sands are SUPPOSED to have high collapsibility.

Discussion

31.	Which of the following equipment can be used for determining the grain size of soil particles?(a) Sprue(b) Gate(c) Runner(d) SieveThe question was posed to me in homework.The doubt is from Grain Size and Shape topic in division Molding and Core Sands of Casting-Forming-Welding I
Answer» The CORRECT option is (d) Sieve For explanation I would say: Analysis of grain size of soils particles containing mostly large size particles is completed by using sieves. It is a device which normally consists of openings of same size and SHAPE through which GRAINS or particles of SOIL passes which should be SMALLER in size as compared to the size of openings, and the very large particles retained on the sieve.

Discussion

32.	Which of the following is not refractory sand?(a) Olivine(b) Silica Sand(c) Dolomite(d) Barium ChlorideThe question was asked in homework.I need to ask this question from Refractory Sands topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct option is (d) BARIUM Chloride To explain I WOULD say: Among the following, Barium Chloride is not refractory SAND, as it is counted under foundry fluxes, whereas all remaining SANDS are refractory sands.

Discussion

33.	The size and shape of particles in the soil cannot reflect material composition and grain formation.(a) True(b) FalseI have been asked this question in an interview.My question comes from Grain Size and Shape in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct CHOICE is (B) False The explanation: The size and shape of particles in the soil reflect the material composition and grain formation. And also include the ESCAPING from a mineral matrix and depositional environments. The COMMON processes involve the formation of small and large size grains in the soil mixture which is used for making mould.

Discussion

34.	Foundry sands cannot be obtained in which of the following states?(a) Uttar Pradesh(b) Punjab(c) Orissa(d) BiharI had been asked this question by my school teacher while I was bunking the class.The question is from Indian Sand and core sand in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct choice is (d) BIHAR The best explanation: FOUNDRY SAND is found to be available in many parts of India LIKE Uttar Pradesh, Punjab and Orissa, but it is not available in the state of Bihar.

Discussion

35.	Foundry sand is found in which part of Maharashtra?(a) Satara(b) Mumbai(c) Nagpur(d) NasikThe question was asked in semester exam.This is a very interesting question from Indian Sand and core sand topic in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct OPTION is (a) SATARA The explanation is: FOUNDRY sand is AVAILABLE in MAHARASHTRA, but it is not available in all parts of the state. It is found only in the parts of Satara.

Discussion

36.	How much should fuel oil be added to increase the moulding ability of sand?(a) 0.01% – 0.1%(b) 0.02% – 0.2%(c) 0.03% – 0.3%(d) 0.04% – 0.4%I had been asked this question in examination.I want to ask this question from Bonding Theory topic in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct choice is (a) 0.01% – 0.1% Explanation: FUEL oils are known to have great PROPERTIES in them. Fuel oils are helpful in ADDING to the increase of the MOULDING ability of sand. It can be ADDED in the range of 0.01% to 0.1%.

Discussion

37.	Pitch maybe used up to what percent?(a) 1%(b) 2%(c) 3%(d) 4%I had been asked this question during an online interview.This question is from Bonding Theory topic in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» The CORRECT choice is (b) 2% To explain: PITCH distillation of soft coals plays a VITAL role in bonding THEORY. Pitch is used for getting a good surface finish on iron CASTS. These pitches generally are used up to be to 2%.

Discussion

38.	Which sand is generally used repetitively for mould making?(a) Silica sand(b) Zircon(c) Olivine(d) DolomiteThis question was posed to me in final exam.This intriguing question originated from Refractory Sands topic in division Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct OPTION is (a) Silica SAND Best EXPLANATION: Silica sand has this as one of its advantages, that it can be used again and again for making moulds. This repetitive use of silica sand MAKES production even more INEXPENSIVE.

Discussion

39.	What does a mould having adequate green strength, does not have?(a) Ability to retain its shape(b) Ability not to get distorted(c) Ability not to collapse(d) Ability to retain hardnessI had been asked this question in my homework.The question is from Properties of Molding Sands topic in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» RIGHT choice is (d) ABILITY to retain hardness The best explanation: For a mould to be having an adequate amount of green strength, it must have RETAINING ability or the ability to GET distorted or to COLLAPSE. A mould having adequate green strength does not have the ability to retain hardness.

Discussion

40.	Which of the following is not used as binders for mould materials?(a) Bentonite(b) Kaolinite(c) Backelite(d) IlliteThe question was posed to me by my college director while I was bunking the class.This question is from Mold Materials topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct answer is (c) Backelite Explanation: Backelite is a MATERIAL which increases hardness BEYOND a limit which is ACCEPTABLE for mold materials as well as its DEFORMATION takes place too early as plastic deformation. Hence, it is not used as a binder.

Discussion

41.	What is the water content in light to medium size malleable iron castings?(a) 3.2%(b) 4.2%(c) 5.2%(d) 6.2%I got this question during an interview for a job.This interesting question is from Preparation of Core Mix in portion Molding and Core Sands of Casting-Forming-Welding I
Answer» The CORRECT option is (B) 4.2% The best I can explain: The water content in terms of percentage composition in light to medium size malleable IRON castings is calculated to be not much in it. The amount of water content found in the CASTING is about 4.2%.

Discussion

42.	What is the dry tensile strength of core sand mixture for general purpose?(a) 15 kg/cm^2(b) 16 kg/cm^2(c) 17 kg/cm^2(d) 18 kg/cm^2This question was addressed to me during an interview.My question comes from Preparation of Core Mix in division Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct choice is (c) 17 kg/cm^2 For EXPLANATION I would say: There are VARIOUS properties of core sand MIXTURE which widely depend on MANY factors. The dry tensile strength of core sand mixture for general purpose is 17 kg/cm^2.

Discussion

43.	What is the melting point of Olivin?(a) 3450°F – 4620°F(b) 3200°F – 3450°F(c) 3100°F – 3220°F(d) 3400°F – 3620°FI had been asked this question in an interview for internship.The doubt is from Indian Sand and core sand in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» Right option is (b) 3200°F – 3450°F Best explanation: ACCORDING to the properties of granular refractories, Olivin has a melting POINT TEMPERATURE of 3200°F to 3450°F. Olivin is one of the materials which do not change its STATE at low temperatures.

Discussion

44.	At what temperature is pitch distilled from soft coals?(a) 400°F(b) 500°F(c) 600°F(d) 700°FI got this question during an interview.The doubt is from Bonding Theory in section Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct answer is (c) 600°F To ELABORATE: For pitch DISTILLATION of soft coals, a decently HIGH temperature level has to be attained. From soft coal, pitch is distilled at a temperature of AROUND 600°F and a by-product called Asphalt is produced.

Discussion

45.	In the green sand moulding of steel casting, what is the moisture percentage composition?(a) 1% – 2%(b) 2% – 3%(c) 3% -4%(d) 4% – 5%I got this question in an interview for job.My query is from Molding Sand Mixtures for Casting in division Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct answer is (c) 3% -4% To ELABORATE: In GREEN sand mouldings of steel castings, the MOISTURE percentage COMPOSITION is CALCULATED to be 3%- 4% and the amount of bentonite present in the same green sand is around 3.5%.

Discussion

46.	The grain size distribution is mainly carried out to determine the strength and permeability of the soil.(a) True(b) FalseThe question was asked in my homework.My question is based upon Grain Size and Shape in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» Right choice is (a) True The explanation is: The grain size distribution is fundamental for determining the PROPERTIES of SOIL. It is mainly CARRIED out for the classification of soil and to estimate the engineering properties like strength, permeability, COMPRESSIBILITY and shear strength. Practically, the grain size distribution of soil is obtained by integrating the data gained from tests like mechanical sieving and HYDROMETER testing.

Discussion

47.	Which of the following would not happen if hot strength is not enough?(a) The mould may get hardened(b) The mould may get enlarged(c) The mould may get eroded(d) The mould may crackI got this question in unit test.I would like to ask this question from Properties of Molding Sands topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» The correct OPTION is (a) The MOULD may get hardened Best EXPLANATION: If there is not an adequate amount of hot strength PROVIDED, then the mould may get enlarged, the mould may get eroded and the mould may crack, but the mould will not get hardened.

Discussion

48.	Which of the following clay binders are most commonly used?(a) Bentonite(b) Illite(c) Limonite(d) KaoliniteThe question was asked in a national level competition.The above asked question is from Molding Sands Binders topic in section Molding and Core Sands of Casting-Forming-Welding I
Answer» The CORRECT OPTION is (a) Bentonite Best explanation: Bentonite is the most commonly USED clay binder because of its ability to produce strong bonds inside the moulding sands. Bentonite is classified into 2 TYPES, namely, Sodium MONTMORILLONITE and Calcium montmorillonite.

Discussion

49.	Which of the following is bentonite?(a) Kaolinite(b) Sodium Montmorillonite(c) Illite(d) LimoniteI got this question by my college director while I was bunking the class.My question comes from Molding Sands Binders in section Molding and Core Sands of Casting-Forming-Welding I
Answer» The CORRECT choice is (b) Sodium Montmorillonite The EXPLANATION is: Bentonite sands are one of the most USEFUL additive in casting sands, as it helps in enhancing its properties. Bentonite is classified into 2 TYPES, namely, Sodium montmorillonite and Calcium montmorillonite.

Discussion

50.	Natural sands are economical than synthetic sands.(a) True(b) FalseI had been asked this question during a job interview.I need to ask this question from Molding Sands in chapter Molding and Core Sands of Casting-Forming-Welding I
Answer» Correct option is (a) True To explain: In natural sands, the amount of availability of it is quite abundant, also, there need not be much of further operations on the natural sands UNLIKE synthetic sands. Natural sands involve a much LESSER cost as COMPARED to synthetic sands, as lesser control is needed there.

Discussion

Explore topic-wise InterviewSolutions in .

Good friability is one of the properties of core sand.(a) True(b) FalseThis question was addressed to me in a national level competition.My question comes from Indian Sand and core sand topic in chapter Molding and Core Sands of Casting-Forming-Welding I

Which of the following sand is freely available?(a) Silica sand(b) Zircon(c) Olivine(d) DolomiteI have been asked this question in an international level competition.My doubt stems from Refractory Sands in section Molding and Core Sands of Casting-Forming-Welding I

Which of the following is the most porous sand?(a) Silica sand(b) Zircon(c) Olivine(d) DolomiteI had been asked this question in an international level competition.The above asked question is from Refractory Sands topic in division Molding and Core Sands of Casting-Forming-Welding I

Illite has a softening point of about 4500°F.(a) True(b) FalseThis question was posed to me in semester exam.The doubt is from Molding Sands Binders in chapter Molding and Core Sands of Casting-Forming-Welding I

On increasing the binder content, what in the moulding sand gets reduced?(a) Hardenability(b) Strength(c) Permeability(d) BrittlenessI got this question in an online quiz.My query is from Molding Sands Binders in portion Molding and Core Sands of Casting-Forming-Welding I

The figure below shows which foundry sand grain shape?(a) Round(b) Sub angular(c) Angular(d) CompoundThe question was posed to me in class test.Enquiry is from Molding Sands in division Molding and Core Sands of Casting-Forming-Welding I

The figure below shows which foundry sand grain shape?(a) Round(b) Sub angular(c) Angular(d) CompoundThe question was asked during an internship interview.The origin of the question is Molding Sands in section Molding and Core Sands of Casting-Forming-Welding I

In synthetic sands of aluminium alloys, what is the bentonite percentage composition?(a) 2-5%(b) 3-5%(c) 4-5%(d) 5-6%The question was asked in final exam.My question comes from Molding Sand Mixtures for Casting in portion Molding and Core Sands of Casting-Forming-Welding I

What is the amount of sea coal needed in cast irons for small casting moulding sands?(a) 1%(b) 2%(c) 3%(d) 4%I got this question in unit test.Query is from Bonding Theory in portion Molding and Core Sands of Casting-Forming-Welding I

In dry sand moulding of steel casting, what is the bentonite percentage composition?(a) 1%(b) 2%(c) 4%(d) 5%This question was addressed to me in a job interview.My doubt is from Molding Sand Mixtures for Casting in chapter Molding and Core Sands of Casting-Forming-Welding I

What is the amount of green permeability in light to medium size malleable iron castings?(a) 34 cc/min(b) 44 cc/min(c) 54 cc/min(d) 64 cc/minThe question was asked during an interview.My query is from Preparation of Core Mix topic in chapter Molding and Core Sands of Casting-Forming-Welding I

It becomes easier to read the bottom part of the meniscus when the hydrometer is in a soil suspension.(a) True(b) FalseThe question was posed to me in final exam.The question is from Grain Size and Shape topic in chapter Molding and Core Sands of Casting-Forming-Welding I

Which refractory sand has the best moulding material?(a) Silica sand(b) Magnesite(c) Zircon(d) OlivineI have been asked this question in quiz.I want to ask this question from Refractory Sands topic in portion Molding and Core Sands of Casting-Forming-Welding I

Parting sand is a type of moulding sand.(a) True(b) FalseI had been asked this question during an interview for a job.The doubt is from Properties of Molding Sands in chapter Molding and Core Sands of Casting-Forming-Welding I

For bonding action of clays, what is the amount of water needed?(a) 1.5%-8%(b) 3.5%-11%(c) 4.5%-12%(d) 5.5%-13%The question was asked during an internship interview.This key question is from Bonding Theory topic in chapter Molding and Core Sands of Casting-Forming-Welding I

Which of the following equipment can be used for determining the grain size of soil particles?(a) Sprue(b) Gate(c) Runner(d) SieveThe question was posed to me in homework.The doubt is from Grain Size and Shape topic in division Molding and Core Sands of Casting-Forming-Welding I

Which of the following is not refractory sand?(a) Olivine(b) Silica Sand(c) Dolomite(d) Barium ChlorideThe question was asked in homework.I need to ask this question from Refractory Sands topic in section Molding and Core Sands of Casting-Forming-Welding I

The size and shape of particles in the soil cannot reflect material composition and grain formation.(a) True(b) FalseI have been asked this question in an interview.My question comes from Grain Size and Shape in portion Molding and Core Sands of Casting-Forming-Welding I

Foundry sand is found in which part of Maharashtra?(a) Satara(b) Mumbai(c) Nagpur(d) NasikThe question was asked in semester exam.This is a very interesting question from Indian Sand and core sand topic in chapter Molding and Core Sands of Casting-Forming-Welding I

Pitch maybe used up to what percent?(a) 1%(b) 2%(c) 3%(d) 4%I had been asked this question during an online interview.This question is from Bonding Theory topic in chapter Molding and Core Sands of Casting-Forming-Welding I

Which sand is generally used repetitively for mould making?(a) Silica sand(b) Zircon(c) Olivine(d) DolomiteThis question was posed to me in final exam.This intriguing question originated from Refractory Sands topic in division Molding and Core Sands of Casting-Forming-Welding I

What is the water content in light to medium size malleable iron castings?(a) 3.2%(b) 4.2%(c) 5.2%(d) 6.2%I got this question during an interview for a job.This interesting question is from Preparation of Core Mix in portion Molding and Core Sands of Casting-Forming-Welding I

What is the dry tensile strength of core sand mixture for general purpose?(a) 15 kg/cm^2(b) 16 kg/cm^2(c) 17 kg/cm^2(d) 18 kg/cm^2This question was addressed to me during an interview.My question comes from Preparation of Core Mix in division Molding and Core Sands of Casting-Forming-Welding I

What is the melting point of Olivin?(a) 3450°F – 4620°F(b) 3200°F – 3450°F(c) 3100°F – 3220°F(d) 3400°F – 3620°FI had been asked this question in an interview for internship.The doubt is from Indian Sand and core sand in chapter Molding and Core Sands of Casting-Forming-Welding I

At what temperature is pitch distilled from soft coals?(a) 400°F(b) 500°F(c) 600°F(d) 700°FI got this question during an interview.The doubt is from Bonding Theory in section Molding and Core Sands of Casting-Forming-Welding I

In the green sand moulding of steel casting, what is the moisture percentage composition?(a) 1% – 2%(b) 2% – 3%(c) 3% -4%(d) 4% – 5%I got this question in an interview for job.My query is from Molding Sand Mixtures for Casting in division Molding and Core Sands of Casting-Forming-Welding I

The grain size distribution is mainly carried out to determine the strength and permeability of the soil.(a) True(b) FalseThe question was asked in my homework.My question is based upon Grain Size and Shape in chapter Molding and Core Sands of Casting-Forming-Welding I

Which of the following clay binders are most commonly used?(a) Bentonite(b) Illite(c) Limonite(d) KaoliniteThe question was asked in a national level competition.The above asked question is from Molding Sands Binders topic in section Molding and Core Sands of Casting-Forming-Welding I

Which of the following is bentonite?(a) Kaolinite(b) Sodium Montmorillonite(c) Illite(d) LimoniteI got this question by my college director while I was bunking the class.My question comes from Molding Sands Binders in section Molding and Core Sands of Casting-Forming-Welding I

Natural sands are economical than synthetic sands.(a) True(b) FalseI had been asked this question during a job interview.I need to ask this question from Molding Sands in chapter Molding and Core Sands of Casting-Forming-Welding I