ChE basics

Question 1

Which one of the following is incombustible ?
H2
CCl4
C2H2
S

Answer 1

CCl4

Question 2

The softness or hardness of a grinding wheel depends upon the type & amount of bonding material used. For general purpose cutter grinding __________ grinding wheel is normally used.

Answer 2

aluminium oxide

Question 3

Tin based white metals are used, where bearings are subjected to

high pressure & load.
low pressure & load.
high temperature.
large surface wear.

Answer 3

high pressure & load

Question 4

Friction factor for fluid flow in pipe does not depend upon the

pipe length.
pipe roughness.
fluid density & viscosity.
mass flow rate of fluid.

Answer 4

pipe length

Question 5

All of the following alloying elements of steel increases hardness but sacrifice ductility, except

nickel
vanadium
molybdenum
chromium

Answer 5

nickel

Question 6

The following type of bonding is strongly directional in solids.

Vander Waal’s
Ionic
Metallic
Covalant

Answer 6

Covalant

Question 7

Fog is an example of colloidal system of

solid dispersed in gas.
solid dispersed in liquid.
liquid dispersed in gas.
gas dispersed in liquid.

Answer 7

liquid dispersed in gas

Question 8

Chromium molybdenum steel can not be welded using __________ welding.
thermit
electrical resistance
oxy-acetylene
any of these

Answer 8

Electrical Resistance

Question 9

Speisses is a mixture of the following:

Arsenides of heavy metals.
Antimonides of heavy metals.
Arsenides & antimonides of heavy metals.
Iron, cobalt and nickel.

Answer 9

Arsenides of heavy metals

Question 10

Auto collimator is used to check

flatness
angle
rotor balancing
roughness

Answer 10

angle

Question 11

In troposphere (the weather domain), the temperature ‘t’ at height ‘h’ above the sea level in metres is given by (where, temperature at sea level is 15°C and t is in °C.)

t = 15 - 0.0065 h
t = 15 + 0.0065 h
t = 0.0035 h - 15
t = 15 - 0.0035 h

Answer 11

t = 15 - 0.0065 h

Question 12

A high pressure boiler generates steam at a pressure greater than __________ kg/cm2 .
10
30
50
80

Answer 12

80

Question 13

Evaporative cooling process employs a combination of cooling and humidification in which the

sensible heat is added.
sensible heat is removed and the latent heat is added.
latent heat is removed.
sensible heat is added and latent heat is removed.

Answer 13

sensible heat is removed and the latent heat is added.

Question 14

Which of the following is not an explosive ?

TNT
CMC
RDX
Lead azide

Answer 14

CMC

Question 15

Maxwell’s thermodynamic relations applies to the

chemical systems in equilibrium.
mechanical systems in equilibrium.
irreversible thermodynamic processes.
reversible thermodynamic processes.

Answer 15

chemical systems in equilibrium.

Question 16

Annealing ofwhite cast iron produces __________ iron.

grey
nodular
malleable
spheroidal

Answer 16

malleable

Question 17

Resistance of an electrical conductor is proportional to its (where, l = length and A = cross-sectional area of the conductor)

A
l
A²
both ‘a’ & ‘b’

Answer 17

both ‘a’ & ‘b’

Question 18

A solar cell converts the sunlight directly into __________ energy.

thermal
electrical
mechanical
chemical

Answer 18

electrical

Question 19

If a nuclear reactor produces more fissile nuclear fuel than it consumes, then it is called a __________ reactor.

critical
breeder
fertile
heterogenous

Answer 19

breeder

Question 20

Wrought iron is never shaped by

casting
cold working
forging
welding

Answer 20

casting

Question 21

Powder metallurgy process does not make metal powder by

atomisation
grinding/milling
hammering
electrolytic deposition

Answer 21

hammering

Question 22

In the blast furnace, incorporation of water vapour in the blast gives the following effect.

Increases the reducing potential of the gas.
Increases the flame temperature.
No significant change occurs.
Increases the hydrogen content in the metal.

Answer 22

Increases the reducing potential of the gas.

Question 23

Pick out the wrong statement.

A ferromagnetic material becomes paramagnetic above the ‘Curie temperature’.
Permanent magnets are made of hard materials, whereas electromagnets require soft magnetic materials.
Soft magnetic materials (e.g., pure iron) have higher permeability and low hysterisis loss and coercive forces.
Tungsten steel and alnico are not hard magnetic materials.

Answer 23

Tungsten steel and alnico are not hard magnetic materials.

Question 24

The usual energy consumption in electric arc furnace steel making is __________ KWh/ton of steel.

60 - 100
400 - 700
1200 -1500
2000 - 2300

Answer 24

400 - 700

Question 25

Maximum permissible air velocity in pipelines is about __________ metre/second. 5 10 20 40

Answer 25

10

Question 26

Area under the stress-strain curve upto the __________ is referred to as the modulus of resilience. yield strength elastic limit proportional limit maximum point

Answer 26

proportional limit

Question 27

__________ is the hardest oxide and is hence used where high wear resistance at high temperature is required. Beryllia Zirconia Alumina Magnesia

Answer 27

Alumina

Question 28

Titanium alloys are welded using the Following process: TIG welding. Submerged arc welding. Butt welding. Electron beam welding.

Answer 28

TIG welding.

Question 29

An alloy of Fe - 0.4 % C is cast iron. hypo-eutectoid steel. hyper-eutectoid steel. eutectoid steel

Answer 29

hypo-eutectoid steel.

Question 30

A material in which the atoms are arranged regularly in some directions but not in others, is termed as 'mesomorphous material'; an example of which is lead glass mica silver

Answer 30

lead

Question 31

In extrusion of metals, which of the following statement is true ? speed of the extruded material is same as that of ram speed. Redundant work is a function of the die angle. Relative motion between the billet surface and the container wall is always present. Hollow ram is used for indirect extrusion.

Answer 31

Hollow ram is used for indirect extrusion.

Question 32

Nuclear fission of one atom of uranium-235 produces the energy equivalent to about __________ MeV. 20 200 500 1000

Answer 32

200

Question 33

Which of the following parameters is not responsible for the heat loss from a hot steam carrying bare pipe surface located in a room without fans ? Emissivity of pipe surface. Diameter & length of the pipe. Temperature of hot pipe surface & that of air in the room. none of these.

Answer 33

none of these

Question 34

Machinability of hard alloys and tool steels is improved by spherodising annealing tempering normalising

Answer 34

annealing

Question 35

Transformation range for ferrous material is the temperature interval during which __________ is formed during its heating. cementite austenite martensite pearlite

Answer 35

austenite

Question 36

Maximum amount of thermal radiation is emitted at all wavelengths at any specified temperature by a/an __________ body. grey black opaque white

Answer 36

grey

Question 37

In condensers used in thermal power plants, steam is normally used in shell side and cooling water on the tube side, because of the reason that A. compared to the mass flow rate of cooling water, the rate of condensation of steam is invariably smaller. B. maintaining vacuum on tube side is more difficult than that on the shell side. C. water velocity can be increased conveniently to increase the overall heat transfer co-efficient because of its lower specific volume compared to steam. D. condenser can act as a storage unit for condensed steam.

Answer 37

C. water velocity can be increased conveniently to increase the overall heat transfer co-efficient because of its lower specific volume compared to steam.

Question 38

Cobalt - 60 is used as a source of __________ in medical therapy & industrial radiography. X-rays γ-rays α-rays β-rays

Answer 38

γ-rays

Question 39

Absolute zero pressure can be attained at a temperature of 0°C 50°K 0°R none of these

Answer 39

0°R

Question 40

The product out from a cupola is called wrought iron pig iron cast iron none of these

Answer 40

cast iron

Question 41

Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as Gr0.25, Gr Gr0.25, Gr0.33 Gr, Gr0.25 Gr0.33, Gr0.25

Answer 41

Gr0.25, Gr

Question 42

If the demand for an item is trebled and the order cost is reduced to one third, then the economic order quantity is trebled. remains unchanged. decreases by a factor of 3. decreases by a factor of 1/3.

Answer 42

remains unchanged.

Question 43

Copper deposits are found in India at the following location: Kudremukh Kolar Khetri Ramagundam

Answer 43

Khetri

Question 44

Electrical conductivities of semi-conductors are of the order of __________ ohm/cm. 10^-3 10³ 10^-15 l0¹⁵

Answer 44

10^-3

Question 45

Corrosion of metals can not be prevented by its tempering chromising aluminising alloying

Answer 45

tempering

Question 46

Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of Grashoff number. Grashoff number & Reynolds number. Reynolds number. Grashoff number & Prandtl number.

Answer 46

Grashoff number & Prandtl number.

Question 47

The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be parabolic hyperbolic straight line none of these

Answer 47

parabolic

Question 48

Energy of the sun arises mainly from __________ reactions. fusion fission combustion none of these

Answer 48

fusion

Question 49

Which of the following fastening devices has a head at one end and a nut fitted to the other ? Bolt Stud Top bolt None of these

Answer 49

Stud

Question 50

Sudden fall of atmospheric pressure by a large amount is an indication of the rain cold wave storm fair weather

Answer 50

storm

Question 51

In chemical dehumidification process wet bulb temperature increases. dry bulb temperature remains constant. dew point temperature increases. dry bulb temperature increases.

Answer 51

dry bulb temperature remains constant

Question 52

Secondary hardening in steels arises out of the precipitation of fine alloy carbides at high temperatures. refinement of ferrite grain size by working. decomposition of retained austenite upon heat treatment. precipitation of complex inter-metal-lics upon heat treatment.

Answer 52

decomposition of retained austenite upon heat treatment.

Question 53

Drills are usually made of cermets high speed steel alloy steel tungsten carbide

Answer 53

high speed steel

Question 54

Tumbling is the process of improving the __________ of the materials/parts. surface finish fatigue limit creep limit surface cleanlineses

Answer 54

surface cleanlineses

Question 55

The __________ of a double acting reciprocating pump as compared to the single acting pump will be almost double. flow output head developed overall efficiency weight

Answer 55

flow output

Question 56

__________ of air does not increase with increase in temperature. Density Thermal diffusivity Viscosity Thermal conductivity

Answer 56

Density

Question 57

Spherical shape of mercury droplets is due to its high viscosity. low surface tension. high density. high surface tension.

Answer 57

high surface tension.

Question 58

Sub zero treatment of steel is done to suppress martensite transformation. enhance its working performance in sub zero atmosphere. reduce the retained austenite in hardened steel. induce temper brittleness after its hardening.

Answer 58

reduce the retained austenite in hardened steel.

Question 59

Air-petrol ratio for maximum power generation in spark ignition engine is about 6:1 12 : 1 18 : 1 24 : 1

Answer 59

12 : 1

Question 60

Which of the following varies as the square root of oil pressure during atomisation of fuel oil through a pressure jet burner ? Output & fineness Velocity Both (a) & (b) None of these

Answer 60

Both (a) & (b)

Question 61

The most suitable material of construction for a sewer to carry sewage under high pressure is asbestos cement steel cement concrete stoneware

Answer 61

steel

Question 62

Filler material used in welding should have __________ as compared to the parent metal to be welded. lower melting temperature same melting temperature same composition both 'b' & 'c'

Answer 62

both 'b' & 'c'

Question 63

Oxygen cylinders used for autogenous (cutting/welding) purposes are seamless & made of steel. heat treated before use. made by sand casting. welded steel cylinders.

Answer 63

seamless & made of steel.

Question 64

Identify the correct statement. Sphlerite is zinc oxide. The first law of the thermodynamics is stated as δE = δQ - δW. Lead can be produced in a blast furnace. T. ferrooxidans is a fungus that can be used for leaching chalcopyrite.

Answer 64

Lead can be produced in a blast furnace.

Question 65

Dowtherm is a high temperature heating medium (a petroleum product). product of coal tar distillation. very heat sensitive material. none of these.

Answer 65

high temperature heating medium (a petroleum product).

Question 66

To counteract the bad effects of strain hardening on a cold formed part, it must be tempered normalised annealed hardened

Answer 66

annealed

Question 67

The dew point temperature lines on psychrometric charts are straight inclined sloping downwards to the right. When relative humidity of moist air is 100%, then wet bulb temperature=dry bulb temperature. wet bulb temperature=dew point temperature. saturation temperature=dew point temperature. all 'a' , 'b' & 'c'

Answer 67

all 'a' , 'b' & 'c'

Question 68

Galvanic corrosion can not be prevented by cathodic protection. anodic protection. usage of largest possible anodic area. any one of these.

Answer 68

anodic protection.

Question 69

Fire in fuel gas pipelines is extinguished most effectively by spraying water. blanketting the area with nitrogen atmosphere. fire fighting foam. none of these.

Answer 69

blanketting the area with nitrogen atmosphere.

Question 70

Which of the following is the most suitable abrasive for grinding high tensile strength materials ? Silicon carbide Corundum Aluminium oxide Boron carbide

Answer 70

Aluminium oxide

Question 71

Case hardening is not done by nitriding hot dipping electroplating both b & c

Answer 71

both b & c

Question 72

Satellites burn off during re-entry to earth's atmosphere, because of the combustion with air. gravitational pull by earth. friction with earth's atmosphere. loss in weight of the satellite.

Answer 72

friction with earth's atmosphere.

Question 73

With increase in compression ratio, the volumetric efficiency of air compressor increases. decreases. remains same. may increase or decrease (depends on the suction pressure).

Answer 73

increases.

Question 74

Neutrons are present in all atoms except that of He C H Ar

Answer 74

H

Question 75

Biological shield in a nuclear reactor is generally provided to protect against the α-rays β-rays gamma rays & neutrons electrons

Answer 75

gamma rays & neutrons

Question 76

__________ circuit is most commonly used to measure strain with the help of a strain gauge. Ballast Voltage balancing potentiometric Simple current sensitive none of these

Answer 76

Voltage balancing potentiometric

Question 77

Which of the following is normally not found in both the S.I. (petrol) & C.I. (diesel) engines ? Air filter Fuel injector Exhaust silencer Battery

Answer 77

Fuel injector

Question 78

__________ is a special constituent of chlorophyll without which photosynthesis is not possible. Calcium Nitrogen Phosphorous Hydrogen

Answer 78

Nitrogen

Question 79

__________ is used as a material of construction for the blade of power saw. Wrought iron Stainless steel Mild steel High speed steel

Answer 79

High speed steel

Question 80

During decarburising of a plain carbon steel, the thickness of ferrite layer growth is proportional to time square root of time square of time cube of time

Answer 80

square root of time

Question 81

Laser welding is widely employed in the __________ industries. electronic structural process heavy

Answer 81

electronic

Question 82

Dryness factor of steam is defined as the ratio of the mass of vapor in the mixture to the mass of the mixture. Dryness factor of steam is measured by a __________ calorimeter. bomb throttling Junker's Boy's

Answer 82

throttling

Question 83

Which of the following is used to produce draught in the locomotive boilers ? Chimney. Induced draught fan. Forced draught fan. Steam jet arrangement.

Answer 83

Steam jet arrangement.

Question 84

Temper brittleness of a material can be fairly detected by the __________ test. fatigue notched bar impact tensile hardness

Answer 84

notched bar impact

Question 85

When the wavelength of incident X-rays increases, the angle of diffraction decreases. increases. remains constant. shows no systematic variation.

Answer 85

decreases.

Question 86

The elastic strain energy of a unit length of an edge dislocation as compared to that of a screw dislocation is more equal less double

Answer 86

more

Question 87

The specific gravity of coal depends mainly on its __________ content. carbon volatile matter ash moisture

Answer 87

moisture

Question 88

In case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is more less equal much more

Answer 88

equal

Question 89

Normalising does not __________ of a metal. improve machinability & tensile strength remove internal stresses refine the structure remove strains caused by cold working

Answer 89

remove internal stresses

Question 90

Which of the following hardness tests does not measure the indentation hardness of metals and alloys ? Vicker's hardness test. Shore sceleroscope test. Brinell hardness test. Rockwell hardness test.

Answer 90

Shore sceleroscope test.

Question 91

With increase in annealing temperature, the following defect density decreases. Vacancy Dislocation Grain boundary All of them

Answer 91

All of them

Question 92

Carnot cycle is also termed as the constant __________ cycle in thermodynamics. entropy pressure volume heat

Answer 92

heat

Question 93

Thermistors are used in __________ devices. voltage measuring temperature measuring temperature compensating both (b) & (c)

Answer 93

both (b) & (c)

Question 94

Broaching tools are usually made of cermets high speed steel tungsten carbide stellite

Answer 94

high speed steel

Question 95

The ratio of the shear stress to the principal stress on a principal plane is 0 1 1/2 1/3

Answer 95

0

Question 96

Minimum safe distance between two liquid fuel storage tanks is equal to (where, H = height of the tank) H H/2 H/4 H/6

Answer 96

H/6

Question 97

Propulsion of rocket follows from the Newton's second law of motion. Newton's third law of motion. law of projectiles. Archimedes principle.

Answer 97

Newton's third law of motion.

Question 98

In multipass welds, shot peening is done after each pass to close the surface porosity. break the continuity of columnar grains. flatten the weldment. introduce texture in the weld.

Answer 98

close the surface porosity.

Question 99

Pick out the correct statement. A. Materials exhibiting high elasticity obey Hooke's law. B. The elastic behaviour of rubber under compression is the same as its behaviour under tension. C. The damping capacity of a material is due to its plastic deformation. D. The stress required to cause plastic flow in polycrystalline material is higher as compared to monocrystalline materials due to the presence of grains of different orientations.

Answer 99

The elastic behaviour of rubber under compression is the same as its behaviour under tension.

Question 100

Consider the equilibrium A(g) + B(g) = AB(g). When the partial pressure of A is 10-2 atm, the partial pressure of B is 10-3 atm and the partial pressure of AB is 1 atm, the equilibrium constant 'K' is 10 atm^-1 10⁵ atm^-1 10 (dimensionless) 10⁵ (dimensionless)

Answer 100

10⁵ atm^-1

Question 101

In the formation of cermets, the ratio of ceramic material to metallic material is usually 80:20. Which of the following is a cermet ? Zirconia Alumina Bakelite Tungsten carbide

Answer 101

Tungsten carbide

Question 102

Enzymes belong to the category of proteins carbohydrates vitamins fats

Answer 102

proteins

Question 103

What is the value of included angle of a triangular notch for maximum discharge ? 30° 60° 90° 120°

Answer 103

90°

Question 104

For separating small pieces of metal from engine oil of a car, the best separating technique is the chromatography evaporation filtration fractional distillation

Answer 104

filtration

Question 105

Heat flow across a hollow sphere of inner radius 'r₁' and outer radius 'r₂' is directly proportional to (r₂-r₁)/(r₁*r₂) (r₁*r₂)/(r₂-r₁) (r₁+r₂)/(r₁*r₂) (r₁*r₂)/(r₁+r₂)

Answer 105

(r₁*r₂)/(r₂-r₁)

Question 106

On oscilloscope screen for dynamic measurement, lissajous diagram is normally used to determine the __________ of the input signal. frequency amplitude damping none of these

Answer 106

frequency

Question 107

Fire refining process is employed in case of tin copper zinc aluminium

Answer 107

copper

Question 108

Larger length & diameter water pipes are made by electrical resistance welding. die casting. semi-centrifugal casting. continuous casting.

Answer 108

semi-centrifugal casting.

Question 109

Carbide tipped cutting tools are manufactured by powder metallurgy techniques and have a composition of 90% tungsten carbide and 10% cobalt. 70% aluminium oxide & 30% silica. 30% nickel, 15% chromium & 55% tungsten. 65% tungsten & 35% zirconium.

Answer 109

90% tungsten carbide and 10% cobalt

Question 110

The temperature at which ferromagnetic material can no longer be magnetised by the outside forces, is termed as the critical point. curie temperature. inversion temperature. eutectic temperature.

Answer 110

curie temperature.

Question 111

Baffles provided on the shell side of a shell and tube heat exchanger are meant for providing support for the tubes. improving heat transfer. both 'a' & 'b'. preventing the fouling of tubes & stagnation of shell side fluid.

Answer 111

both 'a' & 'b'.

Question 112

When an isolated thermodynamic system executes a process, work is done. heat transfer takes place. mass flow occurs across the boundary of the system. no chemical reaction takes place within the system.

Answer 112

no chemical reaction takes place within the system.

Question 113

Brittleness induced due to the presence of sulphur in steel can be reduced by adding manganese magnesium vanadium copper

Answer 113

manganese

Question 114

Atomic __________ of an element is a whole number. weight number volume radius

Answer 114

number

Question 115

The boiling & freezing points on a newly defined temperature scale in degree 'D' are 400°D & 100°D respectively. The temperature reading corresponding to 60°C on this new temperature scale will be equal to __________ °D. 140 180 240 280

Answer 115

280

Question 116

Which of the following is an unconventional source of energy ? Thermal power Hydroelectric power Nuclear-fusion power Solar power

Answer 116

Solar power

Question 117

The product (s) of roasting of a sulphide ore is (are) oxide only. sulphate only. oxide and sulphate. dependent on temperature and partial pressure of oxygen & sulphur dioxide.

Answer 117

oxide only.

Question 118

Which of the following are considered applications of ultrasonic testing ? Determination of elastic constant. Detection of defects in metal. Measurement of material thickness. None of the above.

Answer 118

Detection of defects in metal.

Question 119

Suitability of steel for its use in cable is judged by its strength in tension compression torsion shear

Answer 119

tension

Question 120

Hydrogen in liquid steels is dissolved as tiny gas bubbles. in the atomic form. in the ionic form. in the molecular form

Answer 120

as tiny gas bubbles

Question 121

__________ iron is produced by the annealing of white cast iron. Malleable Nodular Ductile Grey

Answer 121

Malleable

Question 122

The mechanism which changes the value of manipulated variable in response to the output signal from the control unit is called the final control element. on-off control. floating control action. none of these.

Answer 122

final control element.

Question 123

Fahrenheit and Centigrade scales have the same readings at -55° -40° -33° -58°

Answer 123

-40°

Question 124

Which of the following low melting alloy containing bismuth and lead is used for electric fuse ? Wood's metal Babbit metal Monel metal Duralumin

Answer 124

Wood's metal

Question 125

Water-tube boiler is the one, in which water passes through tubes and flue gases around it. tube carrying hot flue gases are immersed in a pool of water. tubes are placed in vertical position. none of these.

Answer 125

water passes through tubes and flue gases around it.

Question 126

Dephosphorisation of molten pig iron is favoured by oxidising and basic slag. reducing and basic slag. high activity co-efficient of phosphorous in metal. oxidising and neutral slag.

Answer 126

reducing and basic slag.

Question 127

In a neutral solution H⁺ ions are absent. OH^- ions are absent. both H⁺ and OH^- ions are present in very small but equal concentration. none of these.

Answer 127

both H⁺ and OH^- ions are present in very small but equal concentration.

Question 128

Which of the following commonly used condenser tube materials has the lowest thermal conductivity? Admirability brass. Stainless steel. Aluminium brass. Titanium.

Answer 128

Stainless steel

Question 129

Strain hardening effect in a metal subjected to cold working is due to the __________ mechanism. fracture dislocation slip twinning

Answer 129

slip

Question 130

A common disinfectant used in village wells for disinfection of water is free chlorine bromine iodine potassium permanganate

Answer 130

potassium permanganate

Question 131

Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs? enthalpy relative humidity wet bulb temperature dew point temperature

Answer 131

dew point temperature

Question 132

Which of the following metals can not be hot worked at room temperature ? Zinc Nickel Lead Tin

Answer 132

Nickel

Question 133

Primary designation of steel is based on its hardness & tensile strength. carbon content. iron content. alloying elements content.

Answer 133

alloying elements content.

Question 134

Steel containing low percentage of nickel, chromium & tungsten are termed as the __________ steel. wrought tool alloy plain carbon

Answer 134

plain carbon

Question 135

Superheating of steam is done at constant enthalpy entropy pressure volume

Answer 135

pressure

Question 136

A cylinderical rod subjected to a tensile strain within the elastic limit undergoes a volume change. If the volume strain is equal to half the tensile strain, then the Poisson's ratio of the rod is 0 0.33 0.44 0.25

Answer 136

0.44

Question 137

The surface tension of a liquid, at critical temperature is indeterminate. zero. infinity. same as that at any other temperature.

Answer 137

zero.

Question 138

Large scale fire on fuel gas line is normally extinguished by water steam foam nitrogen

Answer 138

nitrogen

Question 139

Brazing is the joining of metals without melting the base metal. with a non-ferrous filler. both (a) & (b). neither (a) nor (b).

Answer 139

both (a) & (b).

Question 140

Moist climate is the most favourable factor in the site selection far a steel plant textile factory petroleum refinery coke oven battery

Answer 140

textile factory

Question 141

Dry saturated steam can be converted into superheated steam by increasing its cross-sectional area of flow. passing it through a pressure reducing valve. forcing it downwards through a vertical tube. none of these

Answer 141

passing it through a pressure reducing valve.

Question 142

Pick out the wrong statement. A. Copper is the metal having the highest electronic conductivity. B. Hardenability & weldability of metals are inversely related. C. Covalant bonding formed by sharing of electrons is present in all semi-conductor materials. D. Glass transition temperature applies to 'polymers' but not to 'glasses'.

Answer 142

Copper is the metal having the highest electronic conductivity.

Question 143

Increasing sulphur content in pig iron tends to make it soft hard tough ductile & malleable

Answer 143

hard

Question 144

Oxyacetylene reducing flame is used while carrying out welding on alloy steel grey cast iron mild steel high carbon steel

Answer 144

mild steel

Question 145

M₁₀ index of coke indicates its compressive strength. hardness. abrasion resistance. impact strength.

Answer 145

abrasion resistance

Question 146

Gantt charts are used for streamlining the inventory control production schedule sales forecasting quality control

Answer 146

production schedule

Question 147

In the Bayer's process, bauxite is digested under pressure using H₂SO₄ NaOH NH HCl3

Answer 147

NaOH

Question 148

Circular cross section machine parts which are symmetrical about the axis of rotation are made by hot piercing spinning drawing extrusion

Answer 148

spinning

Question 149

The substance used as a smoke screen in warfare is C₂H₂ SiCl₄ P₂O₅ PCl₅

Answer 149

SiCl₄

Question 150

The same volume of all gases is representative of their specific gravities. densities. gas characteristic constants. molecular weights.

Answer 150

molecular weights.

Question 151

Fluorine is not a constituent of freon chloroform teflon fluorocarbons

Answer 151

chloroform

Question 152

The most commonly used combustion system manufactured in India for the thermal power plant boilers is the __________ combustion system. pulverised fuel travelling grate stoker firing circulating fluidised bed fluidised bed

Answer 152

pulverised fuel

Question 153

During solid state sintering of powders, the following mechanism can be active. Evaporation and condensation. Solid state diffusion processes. Liquid formation in grain boundaries. Creation of more dislocations.

Answer 153

Solid state diffusion processes.

Question 154

The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the 'Curie temperature'. Its value for cobalt is __________ °C. 768 1127 1359 1480

Answer 154

1127

Question 155

Regeneration of molecular seive requires it to be heated to a temperature of about __________ °C. 80-120 200-300 600-800 1000-1100

Answer 155

1000-1100

Question 156

The ultimate strength in tension for steel is __________ times the ultimate strength in shear. 0.5 0.9 1.5 2.5

Answer 156

1.5

Question 157

The activity of pure hydrogen gas at 1000°C and 5 atm pressure is always less than 1. is always greater than 1. can be 5. depends on the choice of the standard state.

Answer 157

depends on the choice of the standard state.

Question 158

Which of the following transducers is most commonly used for the measurement of shock and vibration ? Linear variable differential transducer (LVDT) Dial gauge Accelerometer none of these

Answer 158

Accelerometer

Question 159

The power of a low capacity prime mover is most suitably measured by a __________ type dynamometer. driving transmission absorption none of these

Answer 159

absorption

Question 160

__________ addition increases the depth of hardness of steel. Chromium Nickel Tungsten Vanadium

Answer 160

Chromium

Question 161

The most important consideration in value engineering is the profit maximisation. customer satisfaction. cost reduction. process improvement.

Answer 161

customer satisfaction.

Question 162

Lime contains about 90% CaO. Percentage CaO present in limestone is about 25 50 70 80

Answer 162

50

Question 163

The most important material handling system in an integrated steel plant is the belt conveyor diesel locomotive truck overhead hoists & cranes

Answer 163

diesel locomotive

Question 164

Property of a material to resist a tensile force without giving away is a measure of its stiffness toughness resilience tenacity

Answer 164

tenacity

Question 165

Cast iron has the unique property of high ductility damping characteristics hardness malleability

Answer 165

damping characteristics

Question 166

Steels with high carbon equivalent have poor weldability, because in these steels during welding A. carbon and other alloying elements get oxidised from the weld pool. B. excessive ferrite forms in the heat affected zone leading to poor toughness of the weld. C. martensite forms in the heat affected zone leading to poor toughness/ductility of the weld. D. segregation of carbon and other element occurs in the weld pool leading to poor properties of the weld.

Answer 166

martensite forms in the heat affected zone leading to poor toughness/ductility of the weld.

Question 167

If the pH value of a solution of sodium chloride is 7; then what will be the pH value of the solution after its electrolysis ? 7 < 7 > 7 0

Answer 167

> 7

Question 168

Measurement of the area of the indented surface is not involved in the __________ hardhes testing method. Vicker's Rockwell Knoop Brinell

Answer 168

Rockwell

Question 169

Salvage value is the most flexible criteria for analysing a financial investment. 'Salvaging' means A. disposing off a machine/property on as is where is basis. B. disposing off machine/property, which is no longer useful in the present scenerio. C. mortgaging the obsolete machine/property. D. writing off the obsolete machine/ property.

Answer 169

disposing off machine/property, which is no longer useful in the present scenerio.

Question 170

Super conduction in metals is observed at a temperature of __________ °K. <100 >100 about 273 about 373

Answer 170

>100

Question 171

Springback in sheet metal bending depends on the elastic limit bend radius degree of bend thickness of sheet

Answer 171

thickness of sheet

Question 172

The yield point in fatigue loading compared to that in static loading is less. The ratio of ultimate tensile strength to endurance limit of a material subjected to fatigue loading is 0.5 1 1.5 2

Answer 172

2

Question 173

Which of the following is not used as a fuel in rocket propellaht ? Liquid hydrogen Liquid oxygen Liquid hydrazine Kerosene oil

Answer 173

Liquid oxygen

Question 174

Hypo (sodium thiosulphate) because of its complex forming behaviour is used in photography to remove undecomposed silver bromide as a soluble complex for __________ of the picture. printing developing colour fixation

Answer 174

developing

Question 175

Temperature of hot gases flowing in a pipe is measured by a thermocouple inserted in the thermal well. The thermal well made of __________ will facilitate the most accurate measurement of the temperature. copper steel aluminium brass

Answer 175

copper

Question 176

__________ welding will be the most suitable for butt welding two 20 cms thick boiler drum mild steel plates. Electrical resistance Electroslag Plasma torch Submerged arc

Answer 176

Electroslag

Question 177

Machinability of hard alloys & tool steels is improved by spherodising annealing tempering normalising

Answer 177

annealing

Question 178

LASER stands for Light Amplification by Stimulated Emission of Radiation. has the same intensity as visible light. can't be used for cutting metals. none of these.

Answer 178

stands for Light Amplification by Stimulated Emission of Radiation.

Question 179

__________ forces do not act in case of fluids. Vibratory Centrifugal Elastic Tensile

Answer 179

Tensile

Question 180

Which of the following is not a natural abrasive ? Silicon carbide Quartz Corundum Emery

Answer 180

Silicon carbide

Question 181

The function of a nozzle provided in steam turbine is to throttle down (i.e., reduce) the pressure of steam. convert internal energy into kinetic energy. increase the velocity of steam. all (a), (b) & (c).

Answer 181

all (a), (b) & (c).

Question 182

Which of the following polymers is obtained by copolymerisation of three monomers ? SAN ABS SBR PTFE

Answer 182

ABS

Question 183

Silicon percentage in the silicon steel used for electrical appliances/equipments is 0.3-0.4 12-14 3-4 20-25

Answer 183

3-4

Question 184

Material of construction of foundary crucible is graphite lead porcelain stainless steel

Answer 184

graphite

Question 185

Titanium can be easily welded using __________ welding. submerged arc TIG shielded metal arc electroslag

Answer 185

TIG

Question 186

Feed check valve is used in steam boilers to A. check the water level in the boiler. B. check the feed water flow rate. C. feed high pressure water to boiler and guard against its backflow through it. D. none of these.

Answer 186

feed high pressure water to boiler and guard against its backflow through it.

Question 187

Three elastic constants for a completely anisotropic elastic material which follows the Hooke's law are young's modulus, elastic limit stress and yield stress. Which of the following properties is most sensitive to increase in strain rate ? Tensile strength. Elastic limit. Proportional limit. Yield strength.

Answer 187

Proportional limit.

Question 188

Swaging is a/an __________ operation. piercing forging extrusion drawing

Answer 188

forging

Question 189

Pig iron is made from cast iron. made from wrought iron. the one, which comes out of the blast furnace. free from impurities.

Answer 189

the one, which comes out of the blast furnace.

Question 190

Classification of metal forming processes into hot and cold working is based on the following parameters. Stacking fault energy. Recrystallisation temperature. Solidus temperature. Transformation temperature.

Answer 190

Recrystallisation temperature.

Question 191

Kinematic viscosity of water as compared to that of air is more same 15% more 15% less

Answer 191

15% less

Question 192

Which of the following is the most suitable for removing fine particles (< 1 micron diameter) from air below its dew point ? Venturi scrubber Electrostatic precipitator Cyclone separator Fabric filter

Answer 192

Electrostatic precipitator

Question 193

Which of the following is the terminology used for the temperature at which the phase changes occur in a metal ? Critical temperature. Recrystallisation temperature. Phase transformation temperature. Transition temperature.

Answer 193

Critical temperature.

Question 194

Puddling process is used for converting pig iron into cast iron wrought iron mild steel semi-steel

Answer 194

mild steel

Question 195

Addition of __________ in steel can help in increasing the depth of hardness. nickel chromium vanadium tungsten

Answer 195

vanadium

Question 196

On-off control A. fully opens the final control element, when the measured variable is below the set point. B. fully closes the final control element, when the measured variable is above the set point. C. is a two position control (fully open or fully closed) control adequate to control a process with slow reaction and minimum dead time or transfer lag. D. none of these.

Answer 196

is a two position control (fully open or fully closed) control adequate to control a process with slow reaction and minimum dead time or transfer lag.

Question 197

The tensile load-elongation curve of a metal does not describe work hardening yield stress anisotropy index necking strain

Answer 197

anisotropy index

Question 198

Usual value of the resistance suitable for a wire resistance strain gauge is __________ ohms. 20 80 120 500

Answer 198

120

Question 199

Permanent set in a material is produced by subjecting it to triaxial loading. fatigue loading. stresses beyond the elastic limit. tensile & compressive loads simultaneously.

Answer 199

stresses beyond the elastic limit.

Question 200

The following is a typical anionic collector used in flotation. Ethyl dixanthogen. Trimethyl cetyl ammonium bromide. Potassium ethyl xanthate. lAuryl amine hydrochloride.

Answer 200

Potassium ethyl xanthate.

Question 201

A solution which resists change in its pH value on addition of acid/alkali is called the __________ solution. neutral ideal buffer zero pH

Answer 201

buffer

Question 202

Pick out the wrong statement. Weldability of high carbon steel is poorer compared to low carbon steel. Invar is a magnetic alloy. Magnetic permeability of the diamagenetic material is less than one. Martensitic transformation never goes to complection ( i.e., 100%) at room temperature.

Answer 202

Invar is a magnetic alloy.

Question 203

The bolt is subjected to __________ when the nut is tightened by putting the washer beneath it. tension shear compression bending & tension

Answer 203

tension

Question 204

Which of the following is not categorised as the ore agglomeration process ? Nodulising Pelletising Balling Briquetting

Answer 204

Balling

Question 205

With increase in temperature, the surface tension of water increases decreases remains constant increases linearly

Answer 205

decreases

Question 206

A reduction in thermal resistance during heat transfer does not occur in the A. convection heat transfer by stirring the fluid and cleaning the heating surface. B. conduction heat transfer by reduction in the material thickness and increase in the thermal conductivity. C. radiation heat transfer by increasing the temperature and reducing the emis-sivity. D. none of these.

Answer 206

radiation heat transfer by increasing the temperature and reducing the emis-sivity.

Question 207

Unit of viscosity in CGS system is gm .cm^-1 sec^-1 gm . cm² . sec^-2 gm .cm^-2, sec^-1 gm . cm . sec^-1

Answer 207

gm .cm^-1 sec^-1

Question 208

Shaft/rotor speed is most accurately measured by a frequency counter. tachometer. strobometer. speedometer.

Answer 208

strobometer.

Question 209

__________ test determines the yield strength, Young's modulus of elasticity, percentage reduction in area & percentage elongation of a material. Tensile Fatigue Impact None of these

Answer 209

Tensile

Question 210

The rolling process can not be used to produce plates rods tubes wires

Answer 210

tubes

Question 211

Co-efficient of performance of a Carnot cycle refrigerator operating between - 23°C and + 27°C is 3 5 0.5 1.5

Answer 211

5

Question 212

Presence of nickel & chromium in steel does not raise its elastic limit machining properties ductility resilience

Answer 212

elastic limit

Question 213

Hot extrusion process is not used for making cast iron pipe for domestic water supply. aluminium curtain rods. stainless steel tubes used in furnitures. any of these.

Answer 213

cast iron pipe for domestic water supply.

Question 214

Addition of __________ to steel does not help in improving its machinability. sulphur silicon lead phosphorous

Answer 214

silicon

Question 215

Quartz is a __________ material. diamagnetic ferromagnetic ferroelectric piezoelectric

Answer 215

piezoelectric

Question 216

The units of the rate constant for a second order reaction are sec^-1. mole°. moles¹. sec^-1. moles^-1. sec¹. moles¹. sec¹.

Answer 216

moles^-1. sec¹.

Question 217

The most serious manufacturing defect from fracture toughness point of view is surface roughness pores spherical inclusion crack

Answer 217

crack

Question 218

Leakage in a cooking gas cylinder is detected by radio-isotopes. pouring soap solution on the surface and locating the gas bubbles. halide torch. pungent smell of mercaptans present in the gas.

Answer 218

pungent smell of mercaptans present in the gas.

Question 219

Which of the following is the most wear resistant grade of carbide used for the cutting tools? Aluminium carbide Tungsten carbide Nickel carbide Iron carbide

Answer 219

Tungsten carbide

Question 220

The ratio of mass of a neutron to that of an electron is about 1839. What is the ratio of the mass of a proton to that of an electron? 159 1837 2537 10000

Answer 220

1837

Question 221

Laser is a device to produce gamma rays. microwaves. a beam of white light. a beam of coherent light.

Answer 221

a beam of coherent light.

Question 222

Addition of small amount of __________ to grey cast iron is done to produce nodular grey cast iron. manganese phosphorous magnesium chromium

Answer 222

magnesium

Question 223

Minimum thermal efficiency of a steam boiler may be around __________ percent 25 45 65 20

Answer 223

20

Question 224

The temperature at which the magnetic property of iron disappears (i.e., it becomes non-magnetic) and its electrical conductivity & specific heat also changes, is called the 'Curie point', which is __________ °C. 768 908 1400 1539

Answer 224

768

Question 225

Fatigue limit improvement by over stressing the metal by successively increasing the load is called coaxing. In fatigue failure, the material fails below the yield point. above the yield point. below the elastic limit. at the elastic limit.

Answer 225

below the yield point.

Question 226

The malleability of a material is the property by virtue of which it can be rolled or hammered into thin sheets. Which of the following materials has the maximum malleability ? Lead Copper Aluminium Wrought iron

Answer 226

Lead

Question 227

Particle nature of cathode rays is proved due to the fact that they travel in a straight line. get deflected by magnetic electric field. produce fluorescence. heat the exposed material.

Answer 227

get deflected by magnetic electric field.

Question 228

The most commonly used moderator in nuclear power plants is graphite light water heavy water berellium

Answer 228

graphite

Question 229

Babbit lining is used on brass/bronze bearings to increase the antifriction properties. compressive strength. bearing resistance. wear resistance.

Answer 229

wear resistance.

Question 230

The heat of neutralisation remains constant, when there is a reaction between dilute solutions of strong base and strong acid. base and weak acid. acid and weak base. none of these.

Answer 230

base and strong acid.

Question 231

Joining of thin foils is preferred to be done by gamma rays X-rays microwaves gas welding

Answer 231

microwaves

Question 232

Which of the following metals reacts violently with water ? Mercury Sodium Calcium Magnesium

Answer 232

Sodium

Question 233

A steam carraying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will increase. decrease. remain unaffected. may increase or decrease; depends on the thickness of each layer.

Answer 233

remain unaffected.

Question 234

Damage to metal surface by mechanical action is called pitting corrosion erosion none of these

Answer 234

erosion

Question 235

The escape velocity of a body on earth which is independent of its mass is about __________ km/second. 3 7 11 15

Answer 235

11

Question 236

Which of the following test is used for distinguishing among dry oils, semi-drying oils and non drying oils ? Elaiden test Reichart-Meissl value test Henter value test Iodine value test

Answer 236

Elaiden test

Question 237

The wet bulb temperature is lower in dry air than in wet air at the same temperature. A dry bulb thermometer registers a higher temperature than a wet bulb thermometer except at __________ percent relative humidity. 0 100 50 none of these

Answer 237

100

Question 238

The process of removal of scale formed during hot rolling of steel is termed as descaling shot blasting pickling skimming

Answer 238

pickling

Question 239

A psychrometer does not measure the __________ temperature of moist air. dew point dry bulb wet bulb none of these

Answer 239

dew point

Question 240

An ideal material for making cooking vessels should have high heat capacity. low heat capacity. high thermal conductivity. both (b) and (c).

Answer 240

both (b) and (c).

Question 241

Which of the following approaches the ideal gas behaviour most closely ? Wet steam Saturated steam Superheated steam Saturated water

Answer 241

Superheated steam

Question 242

Which of the following is not the function of a volute casing provided in a centrifugal pump ? To reduce the head loss in discharge. To increase the pump efficiency. To collect liquid from the periphery of the impeller and to transmit it to the delivery pipe at constant velocity. To increase the pump discharge rate.

Answer 242

To increase the pump discharge rate.

Question 243

The pressure outside a bubble/droplet of liquid is __________ the internal pressure. greater than less than equal to unpredictable ; depends on the bubble size

Answer 243

less than

Question 244

Two wires of the same radius & material having length in the ratio of 1 : 2 are stretched by the same force. The strain produced in the two wires will be in the ratio of 1:1 1:2 2:1 1:4

Answer 244

1:1

Question 245

Powder metallurgy technique is used in the production of __________ tools. tungsten carbide high carbon steel high speed steel drilling

Answer 245

tungsten carbide

Question 246

Principal alloying elements of cast tool alloys which have very high wear resistance & high temperature strength are cobalt, chromium & tungsten, cobalt, chromium & nickel. molybdenun, tungsten & chromium. cobalt, zirconium & molybdenum.

Answer 246

cobalt, chromium & tungsten,

Question 247

Which of the following is the most suitable material of construction for the condenser tubes, where the cooling medium is brine (salty water)? Aluminium Copper Titanium Stainless steel

Answer 247

Titanium

Question 248

Which of the following is an ore dressing operation ? Classification Smelting Roasting None of these

Answer 248

Classification

Question 249

Gratings is associated with the measurement of linear displacement. concavity/convexity. surface texture. flatness.

Answer 249

linear displacement.

Question 250

__________ joint is mostly used for joining pipes carrying water at low pressure. Nipple Socket Union Bell and spigot

Answer 250

Socket

Question 251

Adhesives can't be used in the form of pressure sensitive tapes. can't join two dissimilar metals. cure instantaneously after application on a surface. none of these.

Answer 251

none of these.

Question 252

In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C. 20 60 120 ∞

Answer 252

∞

Question 253

Normalising of a casting does not induce stresses in it. refine its grain structure. reduce seggregation. improve its mechanical properties.

Answer 253

induce stresses in it.

Question 254

The swift cup test evaluates the following property of a sheet metal. Stretchability Drawability Bendability None of these

Answer 254

Drawability

Question 255

__________ is the most important element, which controls the physical properties of steel. Manganese Silicon Carbon Vanadium

Answer 255

Carbon

Question 256

The emf of a Deniell cell Zn|Zn²⁺||Cu²⁺|Cu can be increased by decreasing the surface area of the electrodes. increasing the concentration of zinc sulphate solution. increasing the surface area of the electrodes. increasing the concentration of copper sulphate solution.

Answer 256

increasing the concentration of copper sulphate solution.

Question 257

A hot short metal is hard when hot. brittle when cold. brittle when hot. brittle under all conditions.

Answer 257

brittle when hot.

Question 258

Corrosion rate can not be lowered by reducing the __________ of the corroding medium. concentration velocity temperature none of these

Answer 258

concentration

Question 259

Routing in production, planning & control is concerned with the sequence of operation to be performed. progress of work performed. authorisation of work to be performed. balancing of load on machines.

Answer 259

sequence of operation to be performed.

Question 260

A fire tube boiler is limited to a maximum steam pressure of about __________ kg/cm2. 6 18 38 52

Answer 260

18

Question 261

The total frictional resistance to fluid flow does not depend upon the roughness of the surface. fluid pressure. fluid density. fluid velocity.

Answer 261

fluid pressure.

Question 262

Stretcher strains found in a low carbon sheet are associated with the texture. dislocation density. yield point phenomenon. thickness of the sheet.

Answer 262

yield point phenomenon.

Question 263

The most important consideration, while designing the refrigeration system of an aircraft is that the refrigeration system is as light as possible. has very high C.O.P. employs minimum quantity of refrigerant. consumer minimum horse power.

Answer 263

is as light as possible.

Question 264

Though tin occurs lower than iron in the electrochemical series, yet it is coated on steel for corrosion protection, because of its A. lower cost. B. abundant availability. C. resistance to vegetable acids as the tin plate are commercially used in 'canning' industry. D. none of these.

Answer 264

resistance to vegetable acids as the tin plate are commercially used in 'canning' industry.

Question 265

Which of the following is resistant to the action of both heat & chemicals ? Boro silicate glass, Silica glass. Soda lime glass. none of these.

Answer 265

Boro silicate glass,

Question 266

Metallic surveying tapes are made of __________ which has a low co-efficient of expansion & enough strength. invar hastealloy duralumin monel metal

Answer 266

invar

Question 267

Which of the following is a unit of time ? Barn Light year Angstrom none of these

Answer 267

none of these

Question 268

__________ furnace is generally used in the non-ferrous foundaries. Direct arc Indirect arc Resistance Induction

Answer 268

Indirect arc

Question 269

Steel & cast iron pipes are produced by __________ casting. slush die investment true centrifugal

Answer 269

true centrifugal

Question 270

The taper provided on pattern for its easy & clean withdrawal from the mould is termed as the __________ allowance. casting pattern draft distoration

Answer 270

draft

Question 271

Gas turbine normally employs a constant __________ cycle. pressure temperature volume none of these

Answer 271

pressure

Question 272

Which of the following relationships is correct for relating the three elastic constants of an isotropic elastic material (where, E = Young's modulus, G = Modulus of rigidity or shear modulus v = Poisson's ratio) ? E = 2G (1 + v) E = G (1 + v) E = G (1 + v)/2 E = 2G (1 + 2v)

Answer 272

E = 2G (1 + v)

Question 273

Electrostatic separation of minerals from each other is based on their differences in the following property. Densities. Magnetic permeabilities. Electrical conductivities. Hardness.

Answer 273

Electrical conductivities.

Question 274

Natural water contains approximately __________ percent of heavy water. 0.015 0.71 1.2 3.5

Answer 274

0.015

Question 275

The minimum temperature to which the water can be cooled in a cooling tower is the __________ temperature of air. ambient dry bulb dew point wet bulb

Answer 275

dew point

Question 276

The order of a chemical reaction can be determined only experimentally can be determined from the stoichiometry of the reaction. can not be zero. can be fractional.

Answer 276

can be determined from the stoichiometry of the reaction.

Question 277

Pick out the wrong statement. A. Lead can creep under its own weight at room temperature. B. The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement. C. Recrystallisation temperature decreases with decrease in strain in a cold worked metal. D. With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase.

Answer 277

Recrystallisation temperature decreases with decrease in strain in a cold worked metal.

Question 278

Pick out the wrong statement. Reflectivity of gases is very low. Absorptivity for metals is very high. Reflectivity for non-conducting materials is low. Reflectivity of polished surfaces is very high.

Answer 278

Absorptivity for metals is very high.

Question 279

For efficient performance of a blast furnace, the extent of reduction of Wustite (FeO) should be 100% indirect reduction. 100% direct reduction. 50-60% indirect reduction. 30-40% indirect reduction.

Answer 279

50-60% indirect reduction.

Question 280

Identify the false statement A. Martensitic steels are less susceptible to pitting corrosion than austenitic steels. B. Pitting corrosion is usually very localised. C. Hydrogen embrittlement is facilitated by tensile stress. D. Stress corrosion cracking is facilitated by tensile stress.

Answer 280

Martensitic steels are less susceptible to pitting corrosion than austenitic steels.

Question 281

__________ can replace tungsten in high speed steel. Chromium Vanadium Cobalt Molybdenum

Answer 281

Cobalt

Question 282

Production of one ton of paper in Indian paper industry consumes about __________ kWh of electricity. 300 800 1400 2000

Answer 282

1400

Question 283

Fatigue strength of a material can not be increased by cold working hot working shot peening any of these

Answer 283

hot working

Question 284

Steel rods are normally used for concrete reinforcement because concrete and steel have almost equal tensile strength. compressive strength. Young's modulus. thermal co-efficient of expansion.

Answer 284

thermal co-efficient of expansion.

Question 285

Out of the following the refractive index is the highest for glass diamond brine kerosene

Answer 285

diamond

Question 286

Function of blow down valve in a boiler is to maintain the drum level. keep the drum pressure constant. drain out the sludge from the drum. empty the boiler during shutdown.

Answer 286

drain out the sludge from the drum.

Question 287

Insulation of liquid surface can be achieved by __________ on top of its surface. floating hollow polypropylene spheres spraying alumina powder putting cement none of these

Answer 287

floating hollow polypropylene spheres

Question 288

Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50 wt% B is R ln 2 -R ln 2 3 R ln 2 -3R ln 2

Answer 288

R ln 2

Question 289

Out of the following, the lowest packing of atoms exists in __________ crystal lattice structure. hexagonal close, packed (hcp) face centred cubic (fcc) body centred cubic (bcc) simple cubic

Answer 289

simple cubic

Question 290

Cadmium in zinc leach liquor is removed by cementation using zinc iron nickel copper

Answer 290

zinc

Question 291

In electrical resistance welding, distortion results from the use of improper clamping methods electrodes current filler material

Answer 291

clamping methods

Question 292

The conventional mechnical transducer, which converts pressure signal to displacement signal is spring manometer strain gauge none of these

Answer 292

manometer

Question 293

Pick out the wrong statement. A. Seam welding, projection welding & spot welding are the classification of electrical resistance welding. B. Electrode tip in spot welding is of copper and the tip diameter should be equal to t (where, t = plate thickness to be welded) c. In spot welding, two pieces to be joined are overlapped and placed between two electrodes. D. Mild steel sheet can not be spot welded.

Answer 293

Mild steel sheet can not be spot welded.

Question 294

Austempering of steel requires.it to be heated to 875°C followed by sudden cooling to 250-525°C, thereby changing austenite to sorbite bainite martensite troostite

Answer 294

bainite

Question 295

A compact estimate about the amount of materials handling between various work stations is obtained from the gantt chart bin chart string diagram travel chart

Answer 295

travel chart

Question 296

Lead is poured into the joint between two- __________ pipes. mild steel concrete cast iron asbestos cement

Answer 296

cast iron

Question 297

The concentration of (H⁺) ions is 4 x 10^-5 in a solution. Then pH of the solution will be (Given log 4 = 0.6 ) 4.4 5.6 8.4 2.4

Answer 297

4.4

Question 298

Age hardening is connected with babbit metal gun metal stainless steel duralumin

Answer 298

duralumin

Question 299

With decrease in the grain size of a material, its creep resistance increases. decreases. remains constant. either (a) or (b) ; depends on the material.

Answer 299

remains constant.

Question 300

__________ rubber is generally used for making 'O' rings used for vacuum sealings. Natural Neoprene Butadiene Nitrile

Answer 300

Neoprene

Question 301

Gross national product (GNP) means the total value of __________ in a country. goods produced gold reserve earning of the citizens taxes paid

Answer 301

goods produced

Question 302

Energy to be supplied to the radioactive nucleus for the emission of a neutron is __________ MeV. 0.8 7.8 200 10000

Answer 302

0.8

Question 303

The co-ordination number in simple cubic structure is 4 6 8 12

Answer 303

6

Question 304

Out of the following surfaces, the emis-sivity will be minimum for aluminium foil concrete plaster smooth glass

Answer 304

concrete

Question 305

The property of material, by which a given amount of energy is absorbed by it without plastic deformation, is called the resilience toughness ductility impact strength

Answer 305

resilience

Question 306

The size of the tetrahedral void in the closest packing of atoms is __________ that of the octahedral void. equal to greater than less than either (a), (b) or (c); depends on the size of atom

Answer 306

less than

Question 307

__________ the exhaust gas is an indication of the incomplete combustion of fuel. Low temperature of High temperature of High % of CO in High % of CO₂ in

Answer 307

High % of CO in

Question 308

Air/fuel ratio on molar (volume) basis for combustion of methane with theoretical quantity of air with be 9.5:1 12.5:1 15.5 :1 18.5 : 1

Answer 308

9.5:1

Question 309

Frost formation on the evaporator tubes in the domestic refrigerators can be prevented by proper design. decreased compressor power. causes heat loss due to poor heat transfer. is immaterial.

Answer 309

causes heat loss due to poor heat transfer.

Question 310

Function of feed check valve in a boiler is to facilitate circulation of high pressure feed water. check the water level in the boiler drum. prevent the back flow of water. regulate the water flow to boiler.

Answer 310

prevent the back flow of water.

Question 311

Ganister contains maximum percentage of FeO SiO₂ MgO MnO₂

Answer 311

SiO₂

Question 312

Nitrogen is not an essential component of protein urea oils & fats any of these

Answer 312

oils & fats

Question 313

In inventory control theory, the economic order quantity (EOQ) is the lot size corresponding to break even analysis. average level of inventory. optimum lot size. none of these.

Answer 313

optimum lot size.

Question 314

The main charge in blast furnace is usually iron ore & coke. iron ore, coke & air. limestone, coke & iron ore. limestone, sand & iron ore.

Answer 314

limestone, coke & iron ore.

Question 315

The atmospheric temperature during melting of ice/snow (in the atmosphere) decreases increases remains same may increase or decrease ; depends on the altitude where snow melts

Answer 315

decreases

Question 316

At room temperature, F.C.C. crystal structure is observed in lead cupro-nickel titanium tungsten

Answer 316

lead

Question 317

The basic function of the drum in a boiler is to act as a storage for feed water. act as a storage for steam. separate steam from water. remove settling impurities from steam.

Answer 317

separate steam from water.

Question 318

Pick out the wrong statement. A. The X-rays can not be deflected by electric field unlike cathode rays. B. The intensity of X-rays can be measured by ionisation current produced due to the ionisation of gas by X-rays. C. The quality of X-rays can be controlled by varying the anode-cathode voltage. D. Crystal structure of a material can be studied by an electron microscope.

Answer 318

C. The quality of X-rays can be controlled by varying the anode-cathode voltage.

Question 319

Colloids can be purified by dialysis reverse osmosis coagulation peptization

Answer 319

dialysis

Question 320

The most prominent single cause of corrosion in boilertubes, drums, economisers and steam superheaters in a thermal power plant boiler is the water alkalinity & leakage. hydrazine addition during feed water treatment. release of non-condensable gas from water in the boiler. scale formation.

Answer 320

release of non-condensable gas from water in the boiler.

Question 321

Maximum carbon content in cast iron is __________ percent. 3.8 4 4.3 4.6

Answer 321

4.3

Question 322

Screws are specified by their __________ diameters. minor major pitch none of these

Answer 322

major

Question 323

The stress at which extension of the material takes place more rapidly as compared to the increase in load is termed as the __________ point of the material. elastic ultimate yielding breaking

Answer 323

yielding

Question 324

A material being tested for endurance strength is subjected to the __________ load. impact completely reversed dynamic static & dynamic

Answer 324

completely reversed

Question 325

With increase in pressure, the latent heat of steam increases. decreases. remains unchanged. data insufficient; can't be predicted.

Answer 325

decreases.

Question 326

'Flare tower' used in industry is meant for venting off (after burning) the excess inflammable/toxic gases at high pressure. absorbing the pollutant gases from the furnace exhaust. cooling of furnace exhaust gases. none of these.

Answer 326

venting off (after burning) the excess inflammable/toxic gases at high pressure.

Question 327

Which of the following has the highest modulus of elasticity (about 7 x 10⁶ kg/cm²) ? High speed steel Stainless steel Tungsten carbide Superalloys

Answer 327

Tungsten carbide

Question 328

Electrolytic reduction cell used for conversion of calcined Al2O3 to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to achieve very high purity of aluminium (99.9%). keep the electrolyte in liquid condition by the generation of heat. electrolytically dissociate alumina. both(b) & (c).

Answer 328

both(b) & (c).

Question 329

All radiations falling on a black body are refracted reflected transmitted absorbed

Answer 329

absorbed

Question 330

Styrofoam is the commercial name of polyurathene polystyrene polyacrylonitrile polybutadiene

Answer 330

polystyrene

Question 331

Dryness fraction of dry steam is 0 ∞ 1 0.5

Answer 331

1

Question 332

Ceramic materials are organic in nature. stronger in compression than in tension. always amorphous in nature. always bad heat conductors.

Answer 332

stronger in compression than in tension.

Question 333

Which of the following processes follows the hardening process for reducing the hardening strains & increasing the toughness of the steel part? Anodising Tempering Carburising Annealing

Answer 333

Tempering

Question 334

Heat required to raise the temperature of a body by 1 °C is called its heat capacity. specific heat capacity. thermal conductivity. water equivalent.

Answer 334

heat capacity.

Question 335

Coating of zinc over steel is known as cladding galvanising anodising passivation

Answer 335

galvanising

Question 336

Air-petrol ratio in an automotive petrol engine is around 14 : 1 22 : 1 25 : 1 4 : 1

Answer 336

14 : 1

Question 337

The property of material, by which a given amount of energy is absorbed by it, without plastic deformation is called resilience toughness ductility impact strength

Answer 337

resilience

Question 338

Sacrificial anode method is used in the protection of pipelines which are buried underground. Sacrificial anode A. occurs higher in the electro-chemical series of metals. B. is exemplified by magnesium plate. C. is much cheaper than the cathodic base material to be guarded against corrosion. D. all (a), (b) & (c).

Answer 338

D. all (a), (b) & (c).

Question 339

Electrochemical corrosion can occur, only if __________ is present in contact with metal. air oxygen liquid medium gaseous medium

Answer 339

liquid medium

Question 340

Crystallisation of polymers is an undesirable property. Crystallisation of celluloid is prevented by adding glycerol nitro cellulose camphor none of these

Answer 340

none of these

Question 341

Preheating prior to welding is done for the purpose of decreasing cooling rate. facilitating fusion of high melting metals. preventing hot cracking. ensuring full penetration.

Answer 341

decreasing cooling rate.

Question 342

Presence of sulphur in steel reduces the hardness. grain size. tensile strength. toughness & transverse ductility.

Answer 342

toughness & transverse ductility.

Question 343

Frother is added in the froth floatation cell used in ore beneficiation to stabilise the air bubbles (i.e., froth), which will hold the ore particles, but it does not affect the floatability of minerals. Which of the following is not used as a frother? Cresylic acid Xanthaies Pine oil all 'a' 'b' & 'c'

Answer 343

Xanthaies

Question 344

Otto cycle used in spark ignition petrol engines is also known as the constant __________ cycle. volume pressure heat none of these

Answer 344

volume

Question 345

Fire on fuel oil lines can be extinguished by foam steam water carbon dioxide

Answer 345

foam

Question 346

In a furnace with heating element temperature at 1700°C, the dominant machanism of heat transfer will be conduction radiation natural convection forced convection

Answer 346

radiation

Question 347

Optical activity is a/an __________ property. additive constitutive both (a) & (b) neither (a) nor (b)

Answer 347

both (a) & (b)

Question 348

Solution loss reaction occurs in the blast furnace shaft. during pretreatment of hot metal. in the L.D. process. during deoxidation in the ladle.

Answer 348

in the blast furnace shaft.

Question 349

Out of the following materials, the one which generally exhibits an yield point is hard bronze soft brass cold rolled mild steel hot rolled mild steel

Answer 349

hot rolled mild steel

Question 350

The efficiency of a Carnot heat engine operating between absolute temperatures T₁ and T₂ (when, T₁ > T₂) is given by (T₁ - T₂)/T₁. The co-efficient of performance (CO.P.) of a Carnot heat pump operating between T₁ and T₂ is given by T₁/(T₁-T₂) T₂/(T₁-T₂) T₁/T₂ T₂/T₁

Answer 350

T₂/(T₁-T₂)

Question 351

Diamagnetic materials are magnetised by eddy currents only. are non-magnetic and can not be magnetised. are magnetised in direction opposite to the magnetic field. can be magnetised in one direction only.

Answer 351

are magnetised in direction opposite to the magnetic field.

Question 352

In connection with corrosion of metals, passivation is the process that intensifies deterioration. changes the composition of the metal. inhibits further deterioration. none of these.

Answer 352

inhibits further deterioration.

Question 353

With increase in impurities in metals, their corrosion resistances increase decrease remain same may increase or decrease ; depending on the type of metal

Answer 353

decrease

Question 354

Most important property of steels for use in automobile bodies is the formability yield strength toughness resilience

Answer 354

formability

Question 355

Consideration of the creep is the most important in case of the blades of gas turbine. piston of an I. C. engine. flywheel of steam engine. cycle chain.

Answer 355

blades of gas turbine.

Question 356

Non-ferrous alloys used for making cutting tools need not have high abrasion resistance toughness red hardness cutting speed

Answer 356

toughness

Question 357

Hollow shafts can be made as strong as solid shafts by making the twisting moments of both the shafts same. Shafts made by __________ have residual stresses. forging cold rolling hot rolling casting

Answer 357

cold rolling

Question 358

Capacity & power requirement for an air compressor working at high altitude compared to sea-level will be more less same either more or less; depends on the climatic conditions.

Answer 358

less

Question 359

Glycerene is used as a coolant in cooling of some engines instead of water, because its higher boiling point (290°C) increases its heat carrying capacity. compartively less weight of coolant is required. smaller radiator can be used. all a, b & c.

Answer 359

all a, b & c.

Question 360

Cold working of a material results in increase in hardness, which is termed as the __________ hardening. cold work age induction

Answer 360

work

Question 361

Potable water means the water used for fire-fighting cooling drinking evaporation to produce steam

Answer 361

drinking

Question 362

One ton of refrigeration is not equivalent to the heat removal rate of 200 BTU/minute 50 kcal/minute 50 kJ/sec. 3.5 KW

Answer 362

50 kJ/sec

Question 363

Starting friction is low in case of the __________ lubrication. boundary hydrodynamic hydrostatic mixed/semi-fluid

Answer 363

hydrostatic

Question 364

Ultimate strength in tension as compared to that in shear for steel is half one third one and half times one fourth

Answer 364

one and half times

Question 365

Which of the following heat treatment processes is usually applied to castings ? Tempering Annealing Normalising Carburising

Answer 365

Carburising

Question 366

Photographic plates are coated with silver nitrate silver halide calcium silicate metallic silver

Answer 366

silver halide

Question 367

Hardening of steel is not possible, unless it is heated __________ critical point. above the highest above the lowest between the first & second between the second & third

Answer 367

above the lowest

Question 368

Isotropic materials have the same __________ in all directions. induced stresses density elastic properties thermal properties

Answer 368

elastic properties

Question 369

The most important requirement for aluminium industry is the availability of cheap ore electrical power labour & abundant water

Answer 369

electrical power

Question 370

Spheriodising of a material is a/an __________ process. normalising annealing tempering hardening

Answer 370

annealing

Question 371

The trace metal present in insulin is Cu Zn Fe Ni

Answer 371

Zn

Question 372

Cold cracking in the heat affected zone of a high strength steel weld can take place because of the retained austenite. martensite formation. relatively high sulphur content in the base metal. sufficient hydrogen present in the welding arc.

Answer 372

martensite formation.

Question 373

Drossing is a __________ operation. smelting dressing roasting dressing

Answer 373

roasting

Question 374

Most of the phosphorous present in the blast furnace burden enters into hot metal flue gases slag refractory lining

Answer 374

hot metal

Question 375

During sensible heating of humid air relative humidity increases. dew point remains constant. dry bulb & wet bulb temperature increases. both 'b' & 'c'.

Answer 375

both 'b' & 'c'.

Question 376

Iron content in Indian iron ore is about __________ percent. 80-85 60-65 40-45 20-25

Answer 376

60-65

Question 377

The heat treatment to which the steel wire containing > 0.25% carbon is subjected to is full annealing bright annealing patenting none of these

Answer 377

patenting

Question 378

__________ of hard alloy and tool steel is done to make it easily machinable. Case carburising Tempering Normalising Annealing

Answer 378

Tempering

Question 379

Which of the following mainly decides the current to be employed is arc welding ? Electrode size Plate thickness Voltage across the arc Welded portion length

Answer 379

Electrode size

Question 380

Temperature attained in soldering of metals is about __________ °C. 150-300 400-500 650-800 1000-1100

Answer 380

150-300

Question 381

The normal stress is the same in all directions at a point in a fluid, only when the fluid is at rest & has zero viscosity. is frictionless. fluid layer has no motion relative to an adjacent layer of fluid. is incompressible & frictionless.

Answer 381

is incompressible & frictionless.

Question 382

A 2 kg object weighs 1.8 kgf on a spring balance. The value of 'g' at that location in m/sec² is 8.82 9.81 10.88 0.95

Answer 382

8.82

Question 383

In chemical dehumidification of air both specific humidity & dry bulb temperature increases. both specific humidity & dry bulb temperature decreases. specific humidity decreases & dry bulb temperature increases. specific humidity increases & dry bulb temperature decreases.

Answer 383

specific humidity decreases & dry bulb temperature increases.

Question 384

What is the pH of distilled water ? 0 1 7 14

Answer 384

7

Question 385

Pick out the correct statement. A. Hot worked materials are subjected to annealing to remove internal stresses. B. Annealing of steel hardens it slightly C. Normalising of a material induces stresses. D. Tempering of a material improves ductility & toughness but reducess hardness & brittlenes.

Answer 385

Tempering of a material improves ductility & toughness but reducess hardness & brittlenes.

Question 386

Dielectric is an electrical insulating material. of low resistivity is preferred. should have high thermal conductivity. need not defy the corrosive action of chemicals.

Answer 386

is an electrical insulating material.

Question 387

Normalising of an object does not refine coarse grain structure obtained during hot working. improve ductility. improve yield strength. improve machanical properties.

Answer 387

improve ductility.

Question 388

Plasma is a high temperature neutral gas. nothing but ionised gas. a source of steady and highest controllable pressure. formed at very low temperature.

Answer 388

nothing but ionised gas.

Question 389

The machanism involved in the removal of metal in drilling operation is by compression extrusion shearing both 'b' & 'c'

Answer 389

both 'b' & 'c'

Question 390

Thermal conductivity of a material does not depend upon its mass volume surface area all 'a', 'b' & 'c'

Answer 390

all 'a', 'b' & 'c'

Question 391

Carbon supply in pack carburising process is in the form of charcoal calcium carbide hydrocarbon oil graphite

Answer 391

charcoal

Question 392

Water hammer is caused in steam carrying pipelines, because of partial condensation of steam. vibration of the pipeline. high degree of superheat of steam. its exposure to torrential rain.

Answer 392

partial condensation of steam.

Question 393

Powder metallurgy is used to produce high precision components with complex cavities and sharp features. components of large size. porosity free components. components of such alloys whose constituents do not form alloys readily.

Answer 393

porosity free components.

Question 394

Catalyst used in the catalytic converter employed in automobiles to convert CO into CO and for complete oxidation of un-burnt hydrocarbons is nickel cobalt vanadium platinum

Answer 394

platinum

Question 395

For a thermodynamic system undergoing a process, which of the following pairs best expresses the relationship similar to that expressed by the pressure volume plot ? Temperature - entropy. Temperature - pressure. Enthalpy - entropy. Enthalpy-pressure.

Answer 395

Temperature - entropy.

Question 396

The main constituent of bones is CaF₂ Ca₃(PO₄)₂ CaCO₃ CaCl₂

Answer 396

Ca₃(PO₄)₂

Question 397

Globular form of cementite is formed during the __________ process. spherodising hardening annealing normalising

Answer 397

hardening

Question 398

Faraday's law of electrolysis is related to the cation speed. atomic number of the cation. equivalent mass of the electrolyte. none of these.

Answer 398

equivalent mass of the electrolyte.

Question 399

The two elements required to form substitutional solid solution should not have same crystalline structure. same valancy widely differing electronegativity. same atomic sizes.

Answer 399

widely differing electronegativity.

Question 400

Rankine cycle comprises of two isothermal and two __________ processes. isobaric polytropic isentropic none of these

Answer 400

none of these

Question 401

Coating provided on the electrodes used in the arc welding is not expected to add alloying elements. prevent electrode from contamination. stabilise the arc. provide protective atmosphere to weld.

Answer 401

prevent electrode from contamination.

Question 402

Desalination of water makes it potable. makes it non-potable. means distillation of water. none of these.

Answer 402

makes it potable.

Question 403

Viscoelastic behaviour is observed in __________ materials. non-crystalline organic polymeric ceramic all crystalline all amorphous

Answer 403

non-crystalline organic polymeric

Question 404

Probability of cavitation occuring becomes very high, when the local __________ resulting in water bubbles formation, which on rupture cause cavitation pressure falls below the vapour pressure pressure becomes very high temperature becomes low all 'a', 'b' & 'c'

Answer 404

all 'a', 'b' & 'c'

Question 405

Which of the following materials has the poorest electrical conductivity ? Carbon Aluminium Silver Stainless steel

Answer 405

Carbon

Question 406

Pipelines carrying various utilities in chemical industries are identified by their colour codes. The color of pipeline carrying steam is black silver grey green yellow

Answer 406

silver grey

Question 407

What is the percentage of chromium in 18-4-1 high speed steel ? 1 4 18 23

Answer 407

18

Question 408

Preheating before welding is done to make the plate softer. burn oil & grease sticking to plate surfaces. avoid plate distortion. prevent cold cracks.

Answer 408

prevent cold cracks.

Question 409

Thermal diffusivity of a substance is proportional to (where, k = Thermal conductivity) 1/k k k² 1/k²

Answer 409

k

Question 410

Dew point temperature always gives an indication of the __________ of the moist air. dryness moisture content coolness latent heat

Answer 410

moisture content

Question 411

For a first order chemical reaction, the concentration of the reactant decreases __________ with time. linearly exponentially logarithmically inversely

Answer 411

linearly

Question 412

Air standard Otto cycle is more efficient than the diesel cycle for the same heat addition & compression ratio. heat addition & pressure. compression ratio & pressure. cylinder dimension & rpm.

Answer 412

heat addition & compression ratio.

Question 413

In case of brasses, with decreasing zinc percentage and increasing copper percentage, its __________ increases. percentage elongation brinell hardness tensile strength all 'a' , 'b' & 'c'

Answer 413

percentage elongation

Question 414

A suitable lubricant used for watches is metallic soap solution grease palm oil hazel-nut oil

Answer 414

hazel-nut oil

Question 415

Out of the following __________ iron has the best capability to bear sudden & excessive shocks. white cast wrought pig

Answer 415

wrought

Question 416

For the irreversible reaction, C_a+ 2C = C_a C₂ , Δ H°298 = - 60000 J . mole^-1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be 30000 J 60000 J 90000 J 240000 J

Answer 416

90000 J

Question 417

Projection welding & stud welding is categorised as the __________ welding. pressure thermit resistance arc

Answer 417

resistance

Question 418

The driving force for the sintering of a powder compact is strain energy. surface energy. volume energy. stacking fault energy.

Answer 418

surface energy.

Question 419

The amount of water evaporated in kg per kg of fuel burnt in a boiler is called the __________ of a boiler. evaporative capacity evaporation efficiency thermal efficiency steam load

Answer 419

evaporative capacity

Question 420

Volumetric composition of flue gas analysed with the Orsat apparatus is : CO₂ = 12%, O₂ = 8%, CO = nil, N₂ = 80%. This flue gas composition indicates that pure oxygen has been used for combustion. nitrogen percentage in the fuel is very high. excess air has been used for combustion. hydrogen is not present in the fuel.

Answer 420

excess air has been used for combustion.

Question 421

A fluid is termed as the Newtonion fluid, when the shear stress is __________ the velocity gradient. independent of inversely proportional to directly proportional to none of these

Answer 421

directly proportional to

Question 422

Transition from laminar flow to turbulent flow in fluid flow through a pipe does not depend upon the length of the pipe. diameter of the pipe. density of the fluid. velocity of the fluid.

Answer 422

length of the pipe.

Question 423

When the wet steam is throttled but still remains wet at the exit of the throttle valve, then its temperature & dryness fraction respectively decreases & increases. increases & increases. increases & decreases. decreases & decreases.

Answer 423

decreases & increases.