Chemical Engineering MCQs

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CHEMICAL ENGINEERING:
The temperature at which the magnetic property of iron disappears (i.e., it becomes nonmagnetic) and its electrical conductivity & specific heat also changes, is called the ‘Curie point’, which is ________________ °C ?
A. 768
B. 908
C. 1400
D. 1539
Referring to the periodic table of elements, it is found that with increasing atomic number. The atomic size in the same___________________?
A. Period increases
B. Period decreases
C. Group increases
D. Both ‘B’ & ‘C’
With increase in temperature, the electrical conductivity of semiconductors_____________________?
A. Increases
B. Decreases
C. Remain constant
D. Either A. or B. depends on the type of semi-conductor
The only suitable method for hardening the low carbon steel is case hardening. Which of the following is a case hardening process ?
A. Cyaniding
B. Sherardizing
C. Spheroidising
D. None of these
Filler material used in welding should have _________________ as compared to the parent metal to be welded ?
A. Lower melting temperature
B. Same melting temperature
C. Same composition
D. Both ‘B’ & ‘C’
Satellites burn off during re-entry to earth’s atmosphere, because of the ____________________?
A. Combustion with air
B. Gravitational pull by earth
C. Friction with earth’s atmosphere
D. Loss in weight of the satellite
About _________________ ton of coke is required in a cupola to produce one ton of casting ?
A. 0.03
B. 0.3
C. 0.8
D. 1.5
Joining of thin foils is preferred to be done by _____________________?
A. Gamma rays
B. X-rays
C. Microwaves
D. Gas welding
Laser welding is widely employed in the __________________ industries ?
A. Electronic
B. Structural
C. Process
D. Heavy
Which of the following test is used for distinguishing among dry oils, semi-drying oils and non drying oils ?
A. Elaiden test
B. Reichert-Meissl value test
C. Hunter value test
D. Iodine value test
Water flow in the river during flood can be categorized as the _________________ flow ?
A. Unsteady uniform
B. Unsteady non-uniform
C. Steady uniform
D. Steady non-uniform
Lap joints are preferred over butt joints in soldering/brazing, because these joints are _________________?
A. Weaker in tension but stronger in shear
B. Weaker in shear but stronger in tension
C. Stronger in both shear and tension
D. The lap joints are easily made
Gratings is associated with the measurement of____________________?
A. Linear displacement
B. Concavity/convexity
C. Surface texture
D. Flatness
Normalising does not _____________________ of a metal?
A. Improve machinability & tensile strength
B. Remove internal stresses
C. Refine the structure
D. Remove strains caused by cold working
Which of the following approaches the ideal gas behavior most closely ?
A. Wet steam
B. Saturated steam
C. Superheated steam
D. Saturated water
Which of the following hardness tests does not measure the indentation hardness of metals and alloys ?
A. Vickers hardness test
B. Shore scleroscope test
C. Brinell hardness test
D. Rockwell hardness test
Fibre reinforced plastic (FRP) are___________________?
A. Made of glass fibre and thermoplastic resins
B. Anisotropic
C. Made of thermosetting resin and glass fibre
D. Both ‘B’ & ‘C’
Window panes of aeroplanes are normally made of_____________________?
A. Perspex (PMMA)
B. Teflon (PTFE)
C. Bakelite (phenol formaldehyde)
D. Polystyrene
Babbitt lining is used on brass/bronze bearings to increase the____________________?
A. Antifriction properties
B. Compressive strength
C. Bearing resistance
D. Wear resistance
Silicon percentage in silicon steel used for electrical equipments is about______________?
A. 1
B. 4.0
C. 8
D. 14
Galvanic corrosion cannot be prevented by___________________?
A. Cathodic protection
B. Anodic protection
C. Usage of largest possible anodic area
D. Any one of these
Ceramic compounds as compared to metallic compounds ____________________ ?
A. Crystallise faster
B. Resist greater tensile stress at room temperature
C. Have higher melting temperature
D. Are better conductor of electricity at higher temperature
Air-petrol ratio for maximum power generation in spark ignition engine is about_____________________?
A. 6 : 1
B. 12 : 1
C. 18 : 1
D. 24 : 1
In an amorphous material, atoms defy any definite atomic structure and exist in random pattern just like in liquid. Which of the following is an amorphous material ?
A. Tin
B. Lead
C. Zinc
D. Glass
______________ has the highest melting point out of the following ?
A. Tungsten
B. Zirconium
C. Molybdenum
D. Tantalum
The most serious manufacturing defect from fracture toughness point of view is____________________?
A. Surface roughness
B. Pores
C. Spherical inclusion
D. Crack
Out of the following, the best material capable of withstanding shock & vibration without the danger of cracking is ___________________?
A. Malleable iron
B. Grey cast iron
C. Chilled cast iron
D. White cast iron
Fatigue limit improvement by over stressing the metal by successively increasing the load is called coaxing. In fatigue failure, the material fails ?
A. Below the yield point
B. Above the yield point
C. Below the elastic limit
D. At the elastic limit
Which of the following is not the function of a volute casing provided in a centrifugal pump ?
A. To reduce the head loss in discharge
B. To increase the pump efficiency
C. To collect liquid from the periphery of the impeller and to transmit it to the delivery pipe at
constant velocity
D. To increase the pump discharge rate
The capacity of a spring to store energy is called the spring form co-efficient. Stiffness of a spring is measured by the____________________?
A. Ability to absorb shock
B. Capacity to store energy
C. Ratio of the wire & coil diameters
D. Load to produce unit deflection
______________________ is used as a material of construction for the blade of power saw ?
A. Wrought iron
B. Stainless steel
C. Mild steel
D. High speed steel
Addition of silicon to cast iron ___________________?
A. Promotes graphite module formation
B. Improves its ductility
C. Does not promote graphite flakes formation
D. Increases the fluidity of molten metal
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_________________?
A. Wet bulb temperature=dry bulb temperature
B. Wet bulb temperature=dew point temperature
C. Saturation temperature=dew point temperature
D. All ‘A’, ‘B’ & ‘C’
The elastic strain energy of a unit length of an edge dislocation as compared to that of a screw dislocation is____________________?
A. More
B. Equal
C. Less
D. Double
The materials which fracture even at small strains are termed as brittle, while those materials which exhibit an appreciable deformation before failure are termed as__________________?
A. Rigid
B. Tough
C. Ductile
D. Plastic
A steam carrying 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____________________?
A. Increase
B. Decrease
C. Remain unaffected
D. May increase or decrease; depends on the thickness of each layer
Fibrous fracture is normally encountered in the ____________________ materials?
A. Hard
B. Elastic
C. Ductile
D. Brittle
Pick out the wrong statement ?
A. A soft magnetic material should have high permeability and small area of hysteresis loop
B. Poisson’s ratio of high melting point metals is more than unity
C. Solders generally melt at less than 185°C
D. Steel produced by B.O.F process is ideally suited for manufacturing flat product
Fire in fuel gas pipelines is extinguished most effectively by _________________?
A. Spraying water
B. Blanketting the area with nitrogen atmosphere
C. Fire fighting foam
D. None of these
In fluid flow, and heat and mass transfer, one encounters (i) kinematic velocity (μ), (ii) molecular diffusivity (ζ) and thermal diffusivity (α). The units of these quantities are ?
A. μ , α and θ all have units of m/s
B. μ , α and θ all have units of m2/s
C. α and θ have units of m2/s, while μ has unit of m/s
D. α and θ have units of m/s, while μ has unit of m2/s
Addition of small amount of ________________ to grey cast iron is done to produce nodular grey cast iron ?
A. Manganese
B. Phosphorous
C. Magnesium
D. Chromium
Which of the following is the most suitable material of construction for the condenser tubes, where the cooling medium is brine (salty water) ?
A. Aluminium
B. Copper
C. Titanium
D. Stainless steel
There are one octahedral void and ______________ tetrahedral void in the closest packing of atoms ?
A. One
B. Two
C. Three
D. None of these
Temper brittleness of a material can be fairly detected by the ________________ test ?
A. Fatigue
B. Notched bar impact
C. Tensile
D. Hardness
Broaching tools are usually made of____________________?
A. Cermets
B. High speed steel
C. Tungsten carbide
D. Stellite
The main reducing agent in iron blast furnace is____________________?
A. Carbon dioxide
B. Carbon monoxide
C. Oxygen
D. Air
Magnetic permeability of iron is increased by its_____________________?
A. Decarburising
B. Alloying with cobalt
C. Purification
D. Alternate heating & cooling
The escape velocity of a body on earth which is independent of its mass is about ______________________ km/second?
A. 3
B. 7
C. 11
D. 15
Factor of safety is the ratio of the ___________________ stress to the working stress?
A. Tensile
B. Compressive
C. Yield
D. Bearing
Shaft/rotor speed is most accurately measured by a_________________?
A. Frequency counter
B. Tachometer
C. Strobometer
D. Speedometer
In chemical dehumidification process___________________?
A. Wet bulb temperature increases
B. Dry bulb temperature remains constant
C. Dew point temperature increases
D. Dry bulb temperature increases
The material used for coating the welding electrode is termed as the___________________?
A. Flux
B. Slag
C. Protective layer
D. Binder
FeO (s) + CO (g) = Fe (s) + CO2 (g), k = 0. 435 at 1173E; at equilibrium, what will be the number of moles of CO gas required to reduce one mole of FeO at 1173 K ?
A. 1.0
B. 1.3
C. 2.3
D. 3.3
A solution which resists change in its pH value on addition of acid/alkali is called the ____________________ solution?
A. Neutral
B. Ideal
C. Buffer
D. Zero pH
Maraging steels derive their strength from the following mechanism ?
A. A fine, highly dislocated and strong martensite
B. Fine dispersions of inter-metallic of Fe, Ni, Ti etc
C. Fine dispersions of alloy carbides in a ferrite matrix
D. Fine dispersions of Fe3 C nucleated on dislocations in austenite
In an eutectic system, two elements are completely____________________?
A. Soluble in solid state
B. Insoluble in liquid state
C. Insoluble in both solid & liquid state
D. Soluble in liquid state
Hot extrusion process is not used for making____________________?
A. Cast iron pipe for domestic water supply
B. Aluminium curtain rods
C. Stainless steel tubes used in furnitures
D. Any of these
Yield strength of a material is determined by the __________________ test?
A. Creep
B. Tension
C. Compression
D. Endurance
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 ?
A. Bomb
B. Throttling
C. Junker’s
D. Boy’s
_____________________ remains constant during the adiabatic cooling of moist air?
A. Wet bulb temperature
B. Dry bulb temperature
C. Relative humidity
D. Specific humidity
The most commonly used moderator in nuclear power plants is__________________?
A. Graphite
B. Light water
C. Heavy water
D. Beryllium
Basicity [%Cao + %MgO + %SiO2) of the slag in Indian blast furnace is in the range of___________________?
A. 0.7-1.0
B. 1.1-1.4
C. 1.5 – 1.8
D. 2.0 – 2.5
The dew point of moist air becomes ____________________ with decrease in its relative humidity ?
A. Less than the wet bulb temperature
B. More than the wet bulb temperature
C. More than the dry bulb temperature
D. Equal to wet bulb temperature
Thermistors are used in _____________ devices?
A. Voltage measuring
B. Temperature measuring
C. Temperature compensating
D. Both B. & C.
Annealing of cast iron__________________?
A. Softens it to facilitate machining
B. Decreases the free carbon
C. Increases the strength
D. None of these
Catalyst used in the ‘catalytic converter’ employed in automobile exhaust line for complete combustion/oxidation of carbon monoxide, nitrogen oxides and hydrocarbons is__________________?
A. Alumina
B. Platinum
C. Vanadium pentoxide
D. Iron oxide
Silicon percentage in the silicon steel used for electrical appliances/equipments is_________________?
A. 0.3-0.4
B. 12-14
C. 3-4
D. 20-25
____________________ joint is mostly used for joining pipes carrying water at low pressure ?
A. Nipple
B. Socket
C. Union
D. Bell and spigot
Which of the following is an example of stress corrosion ?
A. Season cracking of brass
B. Caustic embrittlement of steel
C. Both A. & B.
D. Neither A. nor (B)
Secondary hardening in steels arises out of the _____________________?
A. Precipitation of fine alloy carbides at high temperatures
B. Refinement of ferrite grain size by working
C. Decomposition of retained austenite upon heat treatment
D. Precipitation of complex inter-metallic upon heat treatment
An ideal material for making cooking vessels should have___________________?
A. High heat capacity
B. Low heat capacity
C. High thermal conductivity
D. Both B. and C.
Drills are usually made of__________________?
A. Cermets
B. High speed steel
C. Alloy steel
D. Tungsten carbide
Pressure exerted by a liquid depends upon its_________________?
A. Surface tension
B. Density
C. Viscosity
D. Buoyancy
Brinell Hardness Number (BHN) for talc is approximately in the range of ____________________?
A. 1-5
B. 20-30
C. 100-150
D. 200-250
Vibration upto 100 kilo hertz can be most accurately measured by a ________________ type accelerometer ?
A. Preloaded spring
B. Piezoelectric
C. Bonded strain gauge
D. None of these
Which of the following is normally not found in both the S.I. (petrol) & C.I. (diesel) engines ?
A. Air filter
B. Fuel injector
C. Exhaust silencer
D. Battery
Silicon crystal can be converted to p-type semi-conductor by doping with__________________?
A. Phosphorous
B. Nitrogen
C. Carbon
D. Boron
Corona discharge is related to the operation of a/an_______________________?
A. Induction motor
B. Electrostatic precipitator
C. Fast breeder reactor
D. Magneto hydrodynamic generator (MHD)
Minimum thermal efficiency of a steam boiler may be around ____________________ percent ?
A. 25
B. 45
C. 65
D. 20
Eutectic reaction for iron-carbon system occurs at a temperature of _______________ °C ?
A. 723
B. 959
C. 1147
D. 1493
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____________________?
A. 10 atm-1
B. 105 atm-1
C. 10 (dimensionless)
D. 105 (dimensionless)
Tesla metre per ampere (T. m/A) is the unit for the measurement of_______________?
A. Magnetic susceptibility
B. Magnetic moment
C. Permeability of free space
D. Flux density
The joint for soldering is supported by binding wire made of ____________________?
A. Mild steel
B. Copper
C. Soft iron
D. Stainless steel
The bolt is subjected to _______________ when the nut is tightened by putting the washer beneath it?
A. Tension
B. Shear
C. Compression
D. Bending & tension
Which of the following is not a characteristic observed in material failure by fatigue fracture ?
A. Plastic deformation of material does not occur
B. Initiation of crack from below the surface does not occur
C. Initiation of crack occurs on the surface of the machine part
D. Presence of both rough & smooth zone with conchoidal markings in smooth zone of the
Leakage in a cooking gas cylinder is detected by___________________?
A. Radio-isotopes
B. Pouring soap solution on the surface and locating the gas bubbles
C. Halide torch
D. Pungent smell of mercaptans present in the gas
Out of the following, the alloy which has equal percentage of constituents, is__________________?
A. White metal
B. Gun metal
C. Duralumin
D. Constantan
The _________________ of a double acting reciprocating pump as compared to the single acting pump will be almost double ?
A. Flow output
B. Head developed
C. Overall efficiency
D. Weight
Which of the following is an example of cathodic protection of metals against corrosion ?
A. Painted steel
B. Galvanised iron
C. Case hardened steel
D. Lead lined reactor
Propulsion of rocket follows from the_________________?
A. Newton’s second law of motion
B. Newton’s third law of motion
C. Law of projectiles
D. Archimedes principle
With increase in ___________________ Knocking tendency in a spark ignition petrol engine decreases?
A. Supercharging
B. Wall temperature
C. Compression ratio
D. Engine speed
A psychrometer does not measure the __________________ temperature of moist air?
A. Dew point
B. Dry bulb
C. Wet bulb
D. None of these
An atom bomb works on the principle of __________________?
A. Nuclear fission
B. Nuclear fusion
C. Both the nuclear fission & fusion
D. Ionisation
Neutrons are present in all atoms except that of ___________________?
A. He
B. C
C. H
D. Ar
Principal alloying element in Elinvar (used for making hair springs for watches) is__________________?
A. Copper
B. Aluminium
C. Nickel
D. Zinc
Between 230 and 370°C, blue brittleness is caused in mild steel because of the_________________?
A. Immobility of dislocation
B. Strain-ageing
C. Increase in Young’s modulus
D. Strain hardening
The units of the rate constant for a second order reaction are__________________?
A. Sec-1. mole°
B. Moles1. sec-1
C. Moles-1. sec1
D. Moles1. sec1
A polymer is termed as an ‘elastomer’, if its percentage elongation is more than 100%. An elastomer is termed as ‘rubber’ if its percentage elongation is more than _______________ percent ?
A. 150
B. 200
C. 300
D. 400
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 ?
A. 0
B. 100
C. 50
D. None of these
Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to ________________ boiling ?
A. Film
B. Nucleate
C. Transition
D. All modes of
Normalising does not ______________________ of a metal ?
A. Improve machinability & tensile strength
B. Remove internal stresses
C. Refine the structure
D. Remove strains caused by cold working
Material of construction of the electrode used in the electric resistance welding is___________________?
A. Stainless steel
B. Graphite
C. Copper
D. Steel
Which of the following is an ore dressing operation ?
A. Classification
B. Smelting
C. Roasting
D. None of these
Shampoos are commercially not available in the form of ___________________?
A. Powder
B. Gaseous mixture
C. Solution
D. Emulsion
In multipass welds, shot peening is done after each pass to__________________?
A. Close the surface porosity
B. Break the continuity of columnar grains
C. Flatten the weldment
D. Introduce texture in the weld
Pick out the correct combination about the role of various additives used in polymers ?
A. Plasticiser: increases the polymer strength
B. Heat stabiliser: increases the maximum service temperature
C. Fillers: Does not affect the property of polymer but increases its weight
D. Lubricants: increases the flexibility of polymers
Which of the following is not used as a bearing material ?
A. Copper-lead alloys
B. Babbitts
C. Bronzes
D. Cermets
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 ?
A. Lead
B. Copper
C. Aluminium
D. Wrought iron
Oxide layer formed on the non-ferrous metal surface after its annealing is__________________?
A. Removed by acid pickling
B. Hammered into the surface
C. Removed with coarse emery cloth
D. Left as such to protect the surface
Case hardening is not done by________________?
A. Nitriding
B. Hot dipping
C. Electroplating
D. Both ‘B’ & ‘C’
Upto the critical radius of insulation, added insulation, will____________________?
A. Increase the heat loss
B. Decrease heat loss and will have no effect beyond that
C. Decrease heat flux
D. Reduce convection heat loss compared to conduction heat less
Chlorine acts as a bleaching agent only in the presence of ______________________?
A. Dry air
B. Pure oxygen
C. Moisture
D. Sunlight
Powder metallurgy technique is used in the production of ____________________ tools ?
0
A. Tungsten carbide
B. High carbon steel
C. High speed steel
D. Drilling
Rain drops falling through atmospheric air attain limited terminal velocity, because of ____________________?
A. Upward thrust due to air
B. Viscous force exerted by air
C. Surface tension effects of water
D. Force of gravity
Volume of blast furnace slag is about _______________ times the volume of hot metal (pig iron) of the same weight ?
A. 1.5
B. 3
C. 5
D. 7
Colour comparator is used to measure the___________________?
A. pH value
B. Electrode potential
C. Colour intensity
D. None of these
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 emissivity
D. None of these
Plastics as a material of construction suffer from the drawback of low_________________?
A. Machinability
B. Density
C. Strength
D. Plastic deformation
The thickness of oxide film is y at time t. If K1, K2 and K3 are the temperature dependent constants, the parabolic law of oxidation is given by __________________?
A. y2 = 2k1t + k2
B. y = k1 ln (k2t + k3)
C. y = k1 t + k2
D. y = k1t3 + k2
Biological shield in a nuclear reactor is generally provided to protect against the__________________?
A. α-rays
B. β-rays
C. Gamma rays & neutrons
D. Electrons
The most detrimental impurity in high pressure boiler feed water is ___________________?
A. Suspended salt
B. Dissolved salt
C. Silica
D. Turbidity
Sub zero treatment of steel is done to____________________?
A. Suppress martensite transformation
B. Enhance its working performance in sub zero atmosphere
C. Reduce the retained austenite in hardened steel
D. Induce temper brittleness after its hardening
In Newton’s law of viscosity, which states that the shear stress is proportional to the _____________ Co-efficient of viscosity is called dynamic or absolute viscosity(where, V = velocity, Vg = velocity gradient) ?
A. V2
B. 1/V2
C. 1/Vg
D. Vg
Which of the following is not categorised as the ore agglomeration process ?
A. Nodulising
B. Pelletising
C. Balling
D. Briquetting
Tumbling is the process of improving the ________________ of the materials/parts ?
A. Surface finish
B. Fatigue limit
C. Creep limit
D. Surface cleanliness
Young’s modulus of a material is the measure of its ___________________?
A. Stiffness
B. Malleability
C. Creep resistance
D. Tensile strength
Which of the following materials has the least scrap value ?
A. Aluminium
B. Stainless steel
C. Brass
D. Copper
Which of the following is used to produce draught in the locomotive boilers ?
A. Chimney
B. Induced draught fan
C. Forced draught fan
D. Steam jet arrangement
Alcohols are not suitable as diesel engine fuel because the cetane number of alcohols is____________________?
A. Very low which prevents their ignition by compression
B. Very high which prevents their ignition by compression
C. Zero
D. None of these
The process of removal of scale formed during hot rolling of steel is termed as_________________?
A. Descaling
B. Shot blasting
C. Pickling
D. Skimming

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