Engineering Materials and Metallurgy

1) The crystal structure of Austenite is (Gate 2011)a) BCCb) FCCc) HCPd) None f the above

2) In grey Cast iron, Carbon is present in the form of a) Cementiteb) Free carbonc) Flakesd) Spheroids

3) Connecting rod is usually made up ofa) Alb) Low Carbon steelc) Medium Carbon Steeld) High Carbon Steel

4) The hardness of steel increases if it containsa) Austeniteb) Martensitec) Pearlited) Cementite

5) Ball of ball bearings are made ofa) Cast Ironb) Mild steelc) Stainless steeld) Caron Chrome steel

6) The temperature at which new grains are formed in metal I scalleda) recrystallation temperatureb) lower critical temperaturec) upper critical temperatured) eutectitic temperature

7) Cast iron contains carbona) Greater than 6.3%b) Less than 0.8%c) Less than 2%d) Greater than 2%

8) High Speed Steel (H.S.S) belongs to the category ofa) low carbon steelb) Medium Carbon Steelc) High Carbon Steeld) Alloy steel

9) Stainless steel containsa) Cr, Fe & Nib) Cr & Nic) Fe & Cd) Cr, Ni, Fe & C

10) Which of the following has the least % of Ca) Malleable Ironb) Pig Ironc) Stainless Steeld) Wrought iron

11) Pearlite is the combination ofa) Ferrite & Cementiteb) Cementite & Gamma Ironc) Ferrite & Graphited) Ferrite & Iron graphite

12) Gun Metal containsa) 70% Cu & 30% Znb) 90% Cu & 10% Pbc) 85-92% of Cu & rest with Tin, Pb and Nid) 70-78% of Cu & rest Tin

13) Melting Point of Fe isa) 1539oCb) 1601 oCc) 1489 oC

d) 1712 oC

14) Blast furnace produces following by reduction of iron orea) Cast ironb) Pig ironc) Wrought irond) Malleable iron

15) Carbon in Fe is an example ofa) substitutional solutionb) interstitial solid solutionc) intermetallic compoundd) all the above

16) An example of amorphous material isa) Zincb) Leadc) Brassd) Glass

17) Mangenese in steel increasesa) Tensile strengthb) Hardnessc) Ductilityd) Malleability

18) Tungsten in HSS providesa) Hot hardnessb) Toughnessc) Wear resistanced) Sharp cutting edge

19) To form basic slag, the following is added a) limeb) cokec) scrapd) Al

20) Machinability of metal depends on a) hardnessb) malleabilityc) brittlenessd) hardness & tensile strength

21) The imperfection in crystal structure of metal is calleda) dislocationb) slipc) fractured) cleavage

22) Normalizing operation is carried out ina) furnaceb) Airc) Waterd) Oil

23) pick up wrong statementa) refining grain structureb) relieving internal stressesc) improving wear resistanced) improving machinability

24) Case hardening is the only method suitable for hardeninga) high alloy steelb) high carbon steelc) low carbon steeld) high speed steel

25) Gibb’s phase rule is given by the expression F is equal toa) C + Pb) C – Pc) C – P -2d) C – P + 2Where F = no of degree of freedom

C= no of componentsP = no of Phases

26) Babbit metal is aa)lead base alloy b) tin based alloy c) both a & b d) none of the above

27 ) Weld decay phenomenon found with a) Cast iron b) mild steel c) non ferrous material d) stainless steel

28) “Killed steels” are those steelsa) which are destroyed by burning b) which after their destruction are recycled to produce fresh metal c) which are deoxidized in the ladle with silicon & aluminium d) in which carbon is completely burnt

29) An allotropic material hasa) fixed structure at all temperature b) b) atoms distributed in random pattern c) different crystal structure at different temperatured) d) none of the above

30) Steel may be manufactured bya) Bessemer process b) duplex process c) open hearth process d) all the above

31) Case hardening isa) Done to get a soft ductile interior with a very hard surfaceb) Done to get hard ductile interior with a very hard surfacec) Followed by temperingd) None of the above

32) Heat treatment process used for castinga) Normalizing b) annealing c) tempering d) hardening

33) Heat treatmenta) is effectively only with certain alloysb) Depends upon cooling ratec) Both a & bd) none of the above

34) Recrystallisation temperature isa) 723 oC

b) 910 oC c) 1400 oC d) 1539 oC

35 ) Recrystallisation temperature depends on a) type and purity of metal b) grain size c) annealing time d) all the above

36) If steel is quenched in water, the structure obtained is known asa) pearlite b) sorbite

c) martensite d) troosite

37) Iron –Carbon alloy containing carbon more than 4.3% is known asa) eutectic cast ironb) hyper - eutectic cast ironc) hypo - eutectic cast irond) none of the above

38 ) Percentage of Carbon in high carbon steels isa) 0.1% to 0.15%b) 0.15 to 0.8%

c) 0.8% to 1.5% d) more than 1.5%

39) Grey cast iron as compared to white cast iron isa) harder b) softer c) same d) none of the above

40) Wrought iron isa) is ductile b) can be easily forged or weldedc) cannot resist sudden & excessive shocksd) all the above

41) When 0.8% of Carbon eutectoid steel is slowly cooled from 750 oC to room temperature ( Gate ’08)

a) austenite transforms to pearlite b) pearlite transforms to austenitec) austenite transforms to martensite d) pearlite transforms to martensite

42) Which of the following cooling methods is best suited for converting Austenite steel into very fine pearlite steel? (Gate ’07)

a) Oil Quenching b) Water Quenching c) air cooling d) furnace cooling

43) Ability of the material to resist penetration by another material, is known as

a) Stifness b) b) ductility c) c) hardnessd) d) plasticity

44 ) Strength of material is the ability to resista) deformation due to stress b) b) fracture due to high load c) c) external forces applied with yielding or break down

d) d) none of the above

45) If a material is heated, its toughnessa) increases b) b) decreases c) c) remains same d) d) none of the above

46) Age hardening is generally applied to a) cast iron b) duralumin c) stainless steel d) brass

47) In flame hardening, the flame used is of a) oil burner b) gas burner c) oxy-acetylene d) none of the above

48) Iron – Carbon equilibrium diagram a) Correlates the microstructure and properties of steel and CIb) Indicates the phase change occurring during heating and cooloingc) Is made by plotting carbon % along X – axis and temperature along

Y-axisd) All the above

49) Brinell hardness number is equal to a) P/ D - √( D2 – d2)b) P/D( D - √( D2 – d2) )c) 2P/ D - √( D2 – d2)d) 2P/D( D - √( D2 – d2) )

Where d = dia of impression

50 ) Heavy duty leaf & coil springs contain Carbon of the order ofa) 0.2% b) 0.5%

c) 0.8% d) 1.0%

Welding Technology

1) Oxygen to acetylene ratio in case of neutral flame isa) 1:1 b) 2:1c) 1:2 d) 0.8:1

2) Carburising flame hasa) 3 Zones b) 2 Zones c) 4 Zones d) 1 Zone

3) Projection Welding isa) continuous spot welding process b) multi spot welding process c) used t form rectangle d) something else

4) Arc length in arc welding should be equal to a) Half of the electrode rod b) Rod diameter c) 2.5 times the dia of rod d) 3times the dia of rod

5) For constructing a tank or bucket, welding used is,a) seam welding b) Forge welding c) cold welding d) pressure gas welding

6) For welding materials like Cu and Brass, the flame used to bea) Oxidizing flame b) Neutral flame c) Carburizing flame d) Arc welding

7) 80% of industrial welding is done bya) D.C

b)A.C c)A.C & D.C d)Transformer

8) Seam welding isa) an arc welding process b) a continuous spot welding process c) a multi spot welding process d) a process used for joining round bars

9) A flux is used in welding to a) Remove the oxides of the metals formed at high Tb) Permit perfect cohesion of the metalsc) Cools and metalsd) Both a & b

10) In case of arc welding, the fluxa) is used from outside in the form of powderb) is coated on the electrodes c) is not used d) none of the above

11) Which of the following metals has the least weld ability?a) Carbon steel b) Ironc) Stainless steeld) Cast iron

12) In resistance welding, the heat generated is given bya) H = (I2 * R ) / T b) H = (I2 * T) / Rc) H = I2 * R * Td) H = (R* T) / I2

13) For cutting operation, the most suitable flame isa) neutral b) oxidizing

c) carburizingd) none of the above

14) Weld splatter refers toa) Fluxb) Welding defectc) Filler materiald) Shield

15) In brazing, the melting point of the filler metal should bea) above 1000oC b) above 800oCc) above 420oCd) above 300oc

16) In neutral flame, temperature of the inner luminous cone is arounda) 1500 oC b) 4500 oCc) 3500 oCd) None of the above

17) Advantage of electron beam welding isa) Joining without the fusion of the metalb) Overall efficiency in energy utilizationc) Capacity of joining thick sectionsd) Capacity of joining precision parts

18) Dye penetrant test is suitable for testing weld defect such asa) Over lapb) Slag inclusionc) Incomplete penetrationd) Surface cracks

19) Choose the Odd process outa) TIG weldingb) Thermit weldingc) Resistance weldingd) Submerged arc welding

20) In which type of welding, a pool of molten metal is used?a)Electroslag b) Submerged Arc c) MIG d) TIG

21) Copper is a) Easily spot weldedb) Very difficult to be spot weldedc) As good for spot welding as any other materiald) Preferred to be welded by spot welding

22) Forge welding is best suited fora) Stainless steelb) High carbon steelc) Cast irond) Wrought iron

23) Which of the carbon steels is most wieldablea) 0.15% Carbon steelb) 0.30% Carbon steelc) 0.50% Carbon steeld) 0.75% Carbon steel

24) In arc welding process the intense heat is developed between the work

and the electrode largely due toa) Currentb) Voltagec) Electrical energyd) Constant resistance

25) Arc stability is better witha) AC weldingb) DC weldingc) Both AC & DCd) Specially designed wave form

26) In arc welding, eyes need to be protected againsta) Intense glareb) Sparksc) Infra red raysd) Ultra violet rayse) Both C & D

27) Which of the following welding process uses non-consumable electrodea) LASER weldingb) MIG weldingc) TIG weldingd) Ion beam welding

28) Laser welding finds widest application ina) Heavy industryb) Structural industryc) Process industryd) Electronic industry

29) Cross – wire welding isa) Multi –spot welding processb) Continuous spot welding processc) Used to form meshd) Used where additional strength is required

30) Low hydrogen electrodes are baked prior to use in order thata) Proper strength is obtainedb) Welding is free from arc blowc) Welding is free from moisture pick upd) Current required is minimum

31) In straight polaritya) Electrode holder is connected to negative and work is positiveb) Electrode holder is connected to positive and work is negativec) Work is positive and holder is earthedd) Holder is positive and work is earthed

32) The maximum temperature occurs ata) Neutral

b) Oxidizingc) Carburizingd) All the above

33) If ‘t’ is the thickness of sheet to be spot welded, then electrode tip dia is equal to a) √tb) tc) 1.5 √td) 2.5 √t

34) In the following welding technique, the flame of the torch is directed against the completed welda) Overhead weldingb) Horizontal weldingc) Forehand weldingd) Back hand welding

35) Solder is essentially aa) Tin-silver baseb) Tin-bismuth basec) Tin-lead based) Silver-lead base

36) The flux in Brazing process is used in the form ofa) Powderb) Liquidc) Pasted) Any of the above

37) Post cleaning is necessary at brazes joint in order to avoida) Scalingb) Slaggingc) Oxidationd) Corrosion

38) Spleter is same asa) Tinb) Zincc) Leadd) Silver

39) Acetylene is stored in the gas cylinders ina) Gaseous formb) Liquid formc) Solid formd) Under high pressure

40) Undercuts in weldments are caused due toa) Low welding currentb) Excessive welding currentc) Wrong fluxd) Greasy and dirty surfaces

41) Electron beam welding is best carried out ina) Inert gasb) Vacuumc) CO2

d) None of the above

42) Pre-Heating is essential for weldinga) Low carbon steelb) Alc) High carbon steeld) None of the above

43) Flux is not required for weldinga) Cast ironb) Brassc) Bronzed) Carbon steel

44) Arc welding includea) Metal arc weldingb) Carbon arc weldingc) Atomic hydrogen weldingd) All the above

45) The DC m/c’s as compared to AC m/c’s requirea) Less maintenanceb) More maintenancec) Equal maintenanced) Something else

46) In case of gas welding, the fluxa) Is used from outside in the form of powderb) Is coated on the electrodesc) Is not usedd) None of the above

47) Resistance welding includea) Butt weldingb) Spot weldingc) Seam weldingd) All the above

48) For welding steel by MIG process, the gas used isa) Pure argon gasb) CO2

c) Argon – oxygen mixtured) Nitrogen

49) Ultrasonic welding is a a) High Temperature joining processb) Pressureless arc welding processc) Cold-joining processd) None of the above

50) Magnetic arc blow isa) A recent welding techniqueb) Used to weld hard materialsc) Occurs when welding near equatord) Phenomenon of occurrence of splatter because of magnetic

fields created in DC arc welding

Metal Casting

1) Investment casting uses pattern made ofa) waxb) clayc) metald) wood

2) Casting process used for ornaments and toys of non-ferrous alloys isa) Slush castingb) Die castingc) Pressed castingd) Investment casting

3) Process of making hollow castings of desired thickness by permanent mould without the use of cores, is known as

a) Permanent mould castingb) Die castingc) Slush castingd) Centrifugal casting

4) Misrun is a casting defect which occurs whena) The pouring temperature is very highb) Gases have been absorbed by the liquid metalc) Sufficient superheat has not been provided to the liquid metald) The alignment is improper

5) The additional of coal dust to the green moulding sand is to improvea) Permeabilityb) Surface finishc) Mouldabilityd) Green strength

6) Surface finish of casting depends upona) Mould dressingsb) Pattern finishc) Fineness of sandd) All of the above

7) A Jolt m/c is used toa) Ram the sand harder at the back of the mould and softer on the pattern

faceb) Ram the sand harder at the pattern face with decreasing hardness

towards the back of the mouldc) Produce uniform packing of sand in the mouldd) Give uniform sand hardness throughout the mould

8) In a cold chamber die casting m/ca) Melting pot is separate from the m/cb) Only non-ferrous alloys with high melting temperature are castedc) Al, Mg,Cu base alloys and other high melting alloys are castedd) All the above

9) A sand slinger is used toa) Ram the sand harder at the back of the mould and softer on the pattern

faceb) Ram the sand harder at the pattern face with decreasing hardness

towards the back of the mouldc) Produce uniform packing of sand in the mouldd) Give uniform sand hardness throughout the mould

10) In the foundry sand “Bentonit” is used asa) Plasticierb) Surface finish improverc) Binderd) Refractory powder

11) Shift is a casting defect whicha) Results in mismatching of the top & bottom parts of a castingb) Is due to enlargement of the mould cavity by metal pressure causing

partial or overall enlargement of the castingc) Occurs near the ingates as rough lumps on the surface of the castingd) Is due to a thin projection of metal not intended as part of the casting

12) Slag inclusion in casting is a

a) Surface defectb) Internal defectc) Superficial defectd) None of the above

13) The most suitable material for die casting isa) Steelb) Cast ironc) Nickeld) Copper

14) Draft on pattern for casting ida) Shrinkage allowanceb) Identification number marked on itc) Taper to facilitate its removal from mouldd) For machining allowance

15) Casting process is preferred for parts havinga) A few detailsb) Many detailsc) No detailsd) Non-symmetrical shape

16) Loose piece patterns area) A sort of split patternb) Used when the pattern cannot be drawn from the mouldc) Similar to core printsd) Never used in foundry work

17) Cores are used toa) Making desired recess in castingb) Strengthen moulding sandc) Support loose piecesd) Remove pattern easily

18) Shrinkage allowance is made up bya) Adding to external and internal dimensionsb) Subtracting from external and internal dimensionsc) Subtracting from external and adding to internal dimensionsd) adding to external and Subtracting from internal dimensions

19) The purpose of gate isa) Feed the casting at the rate consistent with the rate of

solidificationb) Act as reservoir for molten metalc) Help feed the casting until all solidification takes placed) Feed molten metal from pouring basin to gate

20) Lifter is aa) Round sleeveb) A long, flat metal plate fitted with an offset handlec) Used to make or repair corners in the mouldd) Used to scoop sand deep in the mould

21) The purpose of sprue is toa) Feed the casting at the rate consistent with the rate of solidificationb) Act as reservoir for molten metalc) Help feed the casting until all solidification takes placed) Feed molten metal from pouring basin to gate

22) As the size of casting increases, it is often better to use increasingly

a) Fine –grainb) Medium grainc) Coarser graind) Any of the above

23) The purpose of raiser is toa) Feed the casting at the rate consistent with the rate of solidificationb) Act as reservoir for molten metalc) Help feed the casting until all solidification takes placed) Feed molten metal from pouring basin to gate

24) The ratio between the pattern shrinkage allowance of steel and cast iron is about

a) 1:1b) 2:1c) 1:2d) 1:1.5

25) Large and heavy castings are made bya) Green sand mouldingb) Pit mouldingc) Dry sand mouldingd) Pressure moulding

26) Molten iron is desulphurised by adding which of the following to the ladle

a) Carbonb) Ferro-manganesec) Ferro-silicond) Soda ash

27) Cold ducts area) Forging defects due to insufficient fillingb) Pores in weldc) Casting defects due to two streams not able to fuse due to being

coold) Casting defects due to moisture

28) Core prints are used toa) Strengthen coreb) Form seat to support and hold the core in placec) Fabricate cored) All the above

29) The internal hot tear defects in castings can be inspected by the following method:

a) Radiographyb) Visual inspectionc) Damping testd) Fluorescent penetrant test

30) Flogging in foundry practice refers to a) A type of moulding methodb) Removal of sprues and risers

c) A non-destructive testing methodd) Removal of slag during pouring

31) Felting is an operation performeda) Before castingb) After castingc) During castingd) After heat treatment

32) The surface & sub-surface cracks in non-magnetic alloys can be easily located and detected by the following inspection method

a) X-ray testingb) Ultrasonic testingc) Magnetic particle inspection testingd) Dye penetrant testing

33) Drossing in foundry practice refers toa) A method of cleaning the castingsb) An inspection method for castingc) A method of deoxidation of molten metald) Improving finish of castings.

34) Sweep pattern is used for moulding parts havinga) Rectangular shapeb) Elliptical shapec) Uniform Symmetrical shaped) None of the above

35) In Carthias processa) Molten metal if fed into the cavity in metallic mould by gravityb) Metal is proud into die cavity, and after a pre-determined time the

mould is inverted to permit a part of metal still in molten state to flow out of cavity

c) Cavity is filled with a precalculated quantity of metal and a core or plunger is inserted to force the metal into cavity

d) None of the above

36) The pouring temperature for grey cast iron isa) 1000 oCb) 1400 oCc) 1550 oCd) 1650 oC

37) Honey combing / sponginess refers toa) Presence of impurities in molten metalb) Molten metal at low temperaturec) Formation of a number of cavities in close proximity in castingd) Defects due to poor heat treatment

38) Colour scheme is employed on patterns in order to identify thea) Pattern allowancesb) Cope & dragc) Material of patternd) None of the above

39) Semi-centrifugal castinga) Is used to ensure purity and density at extremities of a castingb) Is used to cast symmetrical objectsc) Is used to obtain high density and pure castingsd) Is not used for any purpose

40) Antioch process is aa) Continuous casting processb) Welding processc) Process of making porous mouldd) There is nothing like Antioch process

41) Water pipes of large length & dia are made bya) Semi – centrifugal castingb) Continuous castingc) Sand castingd) Forging

42) Dilatometer is used to find out the following property of moulding sand

a) Permeabilityb) Moisture contentc) Hot strengthd) Compactness

43) Which of the following process is not a casting processa) Carthias processb) Extrusionc) Slush processd) Shell moulding

44) Trowel is aa) A round sleeveb) A long, flat metal plate fitted with an offset handlec) Used to make or repair corners in a mouldd) Used to scoop and deep in the mould

45) Cope in foundry practice refers toa) Bottom half of the moulding boxb) Top half of the moulding boxc) Middle portion half of the moulding boxd) Coating on the mould face

46) The purpose of Chaplets is a) Just like chills to ensure directional solidificationb) To provide efficient ventingc) To support the coresd) Compress moulding sand

47) Which of the following is not a casting defecta) Hot tearb) Blow holec) Scabd) Decarburization

48) Chills are metal inserts of steel that are placed at appropriate locations in the mould walls to

a) Decrease the freezing rateb) Increase the freezing ratec) Help directional solidificationd) Prevent directional solidification

49) Strength & Permeability of served sand related toa) Grain sizeb) Clay-contentc) Hardnessd) Moisture content

50) Which of the following material h as more shrinkage allowances

a) Cast ironb) Brassc) Leadd) Steel

Thermodynamics

1) Which of the following laws is applicable for the behavior of a perfect gasa. Boyle’s lawb. Charles’ lawc. Joule’s lawd. All the above

2) An ideal gas as compared to a real gas at very high pressure occupiesa. More volumeb. Less volumec. Same volumed. No such correlation

3) According to the Dalton’s law, the total pressure of the mixture of gases is equal toa. Greater of the partial pressures of allb. Average of the partial pressure of allc. Sum of the partial pressure of alld. Atmospheric pressure

4) Characteristic gas constant of a gas is equal toa. Cp/Cv

b. Cp-Cv

c. Cv/Cp

d. Cp+Cv

5) Specific heat of air at constant pressurea. 0.17b. 0.21c. 0.24d. 1.0

6) The behavior of gases can be fully determined bya. 1 lawb. 2 lawsc. 3 lawsd. 4 laws

7) No liquid can exist as liquid ata. -273Kb. Vacuumc. Zero pressure d. Centre of earth

8) Absolute Zero pressure will occur a. At sea levelb. When molecular momentum of the system becomes zeroc. At center of the earthd. Under vacuum conditions

9) Intensive property of a system is one whose valuea. Depends on the mass of the system, like volumeb. Does not depend on the same of the system, like

temperature & pressurec. Is not dependent on the path followed but on the stated. Is dependent on the path followed and not on the state

10) Boyle’s law pv=constant is applicable to gases undera. All ranges of pressuresb. Only small range of pressures

c. High range of pressuresd. Steady range of pressures

11) The same volume of all gases would represent theira. Densitiesb. Molecular weightc. Specific weightsd. Specific gravities

12) Which law states that the internal energy of a gas is a function of temperaturea. Charles’ lawb. Joule’s lawc. Boyle’s lawd. There is no such law

13) The equation ( P + a / v2) 9v-b) = R is known asa. Real gas equationb. Maxwell’s equationc. Van der Wall’s equationd. Avogadro’ s equation

14) Which of the following quantities is not the property of the systema. Pressureb. Temperaturec. Heatd. Density

15) Work done is Zero for the following processa. Constant volume b. Free expansionc. Throttlingd. All the above

16) strictly speaking all Engineering processes area. quasi-staticb. thermodynamically in equilibriumc. reversibled. irreversible

17) When a gas flows through a very long pipe of uniform c/s, the flow is approximatelya. Isentropicb. Isobaricc. Isothermald. Isochoric

18) Measurement of temperature is based ona. Thermodynamic processb. 0th law of Thermodynamicsc. 1st law of Thermodynamicsd. 2nd law of Thermodynamics

19) In a carnot cycle, heat is transferred ata. Constant volumeb. Constant pressurec. Constant temperatured. Constant enthalphy

20) A perpetual motion m/c is aa. A thermodynamic m/cb. A hypothetical m/cc. A hypothetical m/c whose operation would violate the laws

of thermodynamicsd. An inefficient m/c

21) Kelvin Plank’s deals with a. Conversion of heatb. Conversion of workc. Conversion of heat into workd. Conversion of work into heat

22) During throttling processa. Heat exchange does not takes placeb. No work is done by expanding steamsc. There is no change of internal energy of steamd. All the above

23) Maxwell’s thermodynamic relation are applicable toa. Reversible process

b. Irreversible processc. Thermodynamic processd. Chemical system in equilibrium

24) Thermal power plant works ona. Carnot cycleb. Joule cyclec. Rankine cycled. Otto cycle

25) The working substance for carnot cycle isa. Atmospheric airb. Air fuel mixturec. Ideal gasd. Steam

26) Expansion in nozzle is a a. Isobaric processb. Isothermal processc. Adiabatic processd. Isochoric process

27) Air std efficiency of a diesel cycle is dependent upona. Ratio of specific heatsb. Cut off ratioc. Adiabatic compression ratiod. All the above

28) A system will be in thermodynamic equilibrium only if it isa. Thermal equilibriumb. Mechanical equilibriumc. Chemical equilibriumd. All the above

29) An isentropic process on T-S diagram is represented by aa. Horizontal lineb. Vertical linec. Inclined lined. Curved line

30) Which of the following is extensive propertya. Entropyb. Internal energyc. Kinetic energyd. All the above

31) Triple point of a pure substance is a point at whicha. Liquid and vapour exist togetherb. Solid and liquid exist togetherc. Solid, liquid & vapour phases exist togetherd. Undefined

32) All gases behave ideally undera. Vacuum conditionb. Low pressure conditionsc. High pressure conditionsd. Super critical pressure

33) The process of sublimation is found to occur in the case ofa. Liquid N2

b. Solid CO2

c. Solid O2

d. Steel

34) A steam nozzle convertsa. Heat energy into useful energyb. Heat energy into kinetic energyc. Potential energy into heatd. Kinetic energy into heat

35) The constant pressure gas turbine works ona. Rankine cycleb. Brayton cyclec. Carnot cycled. Dual cycle

36) Barometric pressure is equal toa. 760 mm Hgb. 0 mm Hgc. 735.6 mm hg

d. 100 mm Hg

37) In a refrigeration m/c, COP will be equal toa. Q2 / (Q1 – Q2)b. Q1 / (Q1 – Q2)c. (Q1 – Q2) / Q1 d. (Q2 – Q1) / Q1

38) The value of entropy at 0 oC is taken asa. 1b. 0c. -1d. Any value

39) Temperature of a gas is produced due toa. Kinetic energy of moleculesb. Repulsion of moleculesc. Attraction of moleculesd. Surface tension of molecules

40) Kinetic theory of gases assumes that the collisions b/w the molecules area. Perfectly elasticb. Perfectly inelasticc. Partly elasticd. Partly inelastic

41) The ratio of two specific heats of air is equal toa. 0.17b. 0.24c. 1.41d. 2.71

42) On weight basis, air contains following parts of Oxygena. 21b. 23c. 25d. 73

43) Isochoric process is one in which

a. Free expansion takes placeb. No mechanical work is done by the systemc. All parameters remains constantd. Mass &energy transfer do not take place

44) An actual engine is to be designed having same efficiency as the carnot cycle. Such proportion isa. Feasibleb. Impossiblec. Possibled. Desierable

45) The constant volume cycle is also calleda. Otto Cycleb. Carnot cyclec. Diesel cycled. Rankine cycle

46) For same compression ratio and for heat addeda. Otto cycle is more efficient than Diesel cycleb. Diesel cycle is more efficient than Otto cyclec. Efficiency depends on the factorsd. None of the above.

47) Second law of thermodynamics definesa. Entropyb. Enthalpyc. Heatd. Internal energy

48) Expansion in nozzle is aa. Adiabatic processb. Isothermal processc. Isobaric processd. Isochoric process

49) work done during process can be determined by ∫ p dV when the process isa. static

b. isothermalc. adiabaticd. quasi – static

50) Some times ice is white in color, its due toa. Cooling rapidlyb. Sub-coolingc. Presence of dissolved air / gases and impuritiesd. Blowing air during freezing process