IndiaBIX Chemical Engineering: Mass Transfer Section 12 Flashcards
With increase in carbon percentage in steel, its
yield stress decreases.
elongation percent increases.
tensile strength increases.
impact strength increases.
tensile strength increases.
Percentage of gaunge is maximum in the ore of
iron
gold
zinc
copper
gold
The forms in which various metals and non metals occur in nature are called minerals. Which of the following is not a metallic ferrous mineral?
Cassiterite
Sphalerite
Chalcopyrite
Calcite
Calcite
Pick out the wrong statement.
Dry bulb temperature, wet bulb temperature & dew point are the same in case of saturated air.
Dew point is reached by cooling the humid air at constant moisture content.
Heating of humid air is done for its dehumidification.
none of these.
Heating of humid air is done for its dehumidification.
The most commonly used material for sewers for carrying sewage in the normal situation is
asbestos cement
stainiess steel
stoneware
cast iron
stoneware
Filler metal is used in __________ welding.
braze
electric spot
projection
seam
braze
Acetylene should never be conveyed through __________ pipe, as it forms an unstable compound that dissociates violently at the slightest shock.
stainless steel
copper
aluminium
brass
copper
Which of the following contains the least percentage of carbon ?
Pig iron
Wrought iron
Cast iron
Malleable iron
Wrought iron
Electric arc furnace is employed mainly for the production of __________ steel.
high carbon
alloy
mild
plain carbon
alloy
Heat treatment of steel is done mainly to change its
mechanical properties.
physical properties,
chemical composition.
all ‘a’, ‘b’ & ‘c’.
mechanical properties.
__________ method of depreciation calculation ensures that the interest is charged on the cost of machine asset every year on the book value, but the rate of depreciation remains constant every year.
Annuity charging
Atraight line
Ainking fund
None of these
Atraight line
Main alloying element in Elinvar used in precision instruments, hair springs for watches etc. is
chromium
nickel
zinc
aluminium
nickel
Color of brass changes from yellow to __________ after its dezincification which exemplifies selective leaching.
grey
red
orange
violet
red
Heat dissipation in cooling towers is mainly by
conduction
convection
evaporation
radiation
evaporation
In BOF, desiliconisation is a first order reaction. So the silicon content of the metal decreases
linearly with time.
exponentially with time.
logarithmically with time.
in proportion to the square root of time.
linearly with time.
Hoope’s cell is predominantly used for the electrolytic refining of
zinc
copper
aluminium
tin
aluminium
Lead percentage in pure galena is about
8.6
86.6
35.8
61.4
8.6
Pick out the wrong statement.
Erosion corrosion which is identified by surface grooves, occurs due to the combined action of corrosive environment and mechanical abrasion.
Stress corrosion occurs due to the combined action of corrosive environment and the compressive stress.
Stainless steel is prone to stress corrosion in solution containing chloride ion.
In case of stress corrosion, the direction of crack propagation is perpendicular to the applied tensile stress.
Stress corrosion occurs due to the combined action of corrosive environment and the compressive stress.
The life of a ball bearing is inversely proportional to
(load)1
(load)2
(load)3
(load)0.33
(load)3
Pick out the wrong statement.
Partnership is suitable for medium size business.
A certain minimum of subscription of capital is required for legally starting a business in a Public Limited Joint Stock Company.
Public Limited Joint Stock Company is legally bound to issue prospectus after registration.
A small scale industry is the one, which has a minimum capital investment of Rs. 50 lakhs and maximum 100 lakhs.
A small scale industry is the one, which has a minimum capital investment of Rs. 50 lakhs and maximum 100 lakhs.
Stoneware pipes used for sewers for carrying sewage normally is joined by __________ joint.
spigot and socket
flanged iron
collar
expansion
spigot and socket
Which of the following parameters is actually measured during tensile testing of a specimen using Universal testing machine?
Load & elongation.
Engineering stress & strain.
True stress & strain.
Poisson’s ratio & Young’s modulus.
Load & elongation.
End cooler’ or ‘after cooler’ is employed in air compressor mainly to
remove oil vapour or moisture from air.
cool the dry air before use.
reduce the volumetric capacity of receiver.
none of these.
remove oil vapour or moisture from air.
Streaklines, streamlines & pathlines are almost identical for __________ fluid flow.
ideal
uniform
steady
none of these
steady
The suction and delivery pressure for a two stage compressor are 1 and 25 atm respectively. The intermediate stage pressure would be around __________ atm.
5
10
15
20
5
The term ‘Value’ in value engineering technique refers to the __________ cost of the product.
function (utility)
selling
production
total
function (utility)
Melting point & boiling points of liquid oxygen are respectively - 218.8°C & - 183°C, while the same for liquid nitrogen is - 210°C & - 195.8°C respectively. The difference in melting points of liquid oxygen & liquid nitrogen is not equal to 8.8
°C
°F
°K
°R
°F
The entropy change for a spontaneous process is
> 0 for the system.
< 0 for the system.
> 0 for the system & the surrounding.
< 0 for the system & the surrounding.
< 0 for the system & the surrounding.
Milligram of KOH required to saponify 1 gm of oil is called its __________ number.
saponification
acid
precipitation
emulsion
saponification
Pick out the wrong statement about a fast breeder reactor.
uses molten sodium as moderator.
converts fertile fuel into fissile fuel.
requires highly enriched fuel.
produces more fuel than it consumes.
uses molten sodium as moderator.
The speed of sound will be maximum in
vacuum
metal
air
water
metal
Work done by a/an __________ process is determined by.
adiabatic
quasi-static
isothermal
isentropic
quasi-static
In case of water (Prandtl number ≈ 6) flowing over a flat plate heated over the entire length, the thermal boundary layer thickness as compared to hydrodynamic boundary layer thickness is
less
more
equal
unpredictable
less
__________ number is sometimes used in place of Grashoff number in free convection heat transfer.
Stanton
Brinkman
Rayleigh
Nusselt
Rayleigh
Wrought iron does not have the
uniform strength in all directions.
ability to hold protective coating.
high ductility & corrosion resistance.
easily weldable characteristics.
uniform strength in all directions.
Nitriding of steel is a process for
case hardening
spheroidising
normalising
annealing
case hardening
The maximum percentage of chromium that can be added to steel is about
12
18
24
30
18
Holes in a plate for rivetted joints is preferably made by
drilling
tapping
reaming
punching
drilling
The temperature at which a gas, when subjected to Joule-Thomson expansion, neither cools or heats up, is termed as the __________ temperature. Above this temperature the gas heats up on throttling and below this the gas cools down.
isotactic
saturation
inversion
throttling
inversion
Source of heat supply in a cupola is
coke
charcoal
lumpy coal
pulverised coal
coke
Machine tool bodies are usually made of
cast iron
mild steel
wrought iron
copper alloys
cast iron
Out of the following, the best material capable of withstanding shock & vibration without the danger of cracking is
malleable iron
grey cast iron
chilled cast iron
white cast iron
malleable iron
On increasing the yield strength of a steel from 450 to 650 MPa, its __________ will increase.
ultimate tensile strength (UTS)
modulus of toughness
percent elongation
modulus of resilience
modulus of toughness
The refractory brick which has good thermal shock resistance at high temperature but cracks on cooling below 400°C is
magnesite
chrome
silica
fireclay
silica
The path and movements followed by men, materials & equipments in executing the activities is indicated by the
travel charts
man-machine charts
string diagram
flow diagram
flow diagram
No cutting fluid is normally used, while machining
cast iron
aluminium
mild steel
stainless steel
cast iron
An orthotropic material is a special class of anisotropic material, which is described by their properties in three perpendicular directions. An example of orthotropic material is
stainless steel
cast iron
wood
teflon
wood
pH value of rain water in India ranges from
5.5 to 7.5
8 to 9.5
3.5 to 5
9.5 to 10.5
5.5 to 7.5
The capital & running costs of similar machines having unequal service life can be compared by the __________ method.
equivalant annual cost
rate of return
present net worth
capitalised cost
capitalised cost
Pick the odd man out.
Austempering
Martempering
Cyniding
Parkerizing
Parkerizing
