What type of bond exists predominantly in sodium chloride crystal ?
ionic bond
metallic bond
covalent bond
polar bond
Pure metal A undergoes an isothermal transformation in which its crystal structure changes from face centered cubic FCC to body centered cubic BCC. As a result, the volume of a piece of metal A
increased
decreased
remains the same
decreased up to the midpoint of the transformation and then asymptotically reaches its original value
Which of the following leads to a reduction in the electrical resistivity of a pure metal ?
annealing
cold working
grain refinement
addition of alloying elements
The rigidity of polymer can be increased by
all of these
increase in degree of polymerization
increase in the extent of cross linking
crystallization
Which of the following properties of a metal is insensitive to microstructure ?
modulus of elasticity
tensile strength
ductility
hardness
The dominant charge carriers in phosphorus - doped silicon crystal at room temperature are
electrons
electron holes
protons
silicon ions
Metals are conductive because
the electrons are loosely bound to the nuclei and therefore mobile
they have a characteristic metallic luster
they have extra electrons as exhibited by normally positive valence states
they are on the left side of the periodic table
An X - ray is
an electromagnetic radiation
a ray of electrons
a ray of helium nuclei
not known, hence the name " x " ray
An electron - volt is
a unit of energy equal to the energy possessed by an electron accelerating through a potential of one volt
a voltage unit commonly used when measuring the voltage of the electrons
the unit of electrical charge of one electron
none of the above
Group IA are easily ionized because
they have a single "s" electrons in the outer orbit
they are metals and therefore conductive
they react violently in water to liberate hydrogen
they have relatively low melting points for metal
The rare earth metals all have very similar chemical properties because :
successive members of the series are formed by adding 4f electrons which have little effect on the reactivity
they are rare, hence little is known about their chemistry
they melt at extreme temperatures, hence are nearly inert
they are in separate row at the bottom of the periodic table
Which of the following group of elements all form crystals of diamond structural lattice ?
carbon, silicon, germanium
carbon, boron, aluminum
carbon, cobalt, nickel
lithium, sodium, potassium
The stress or load where a crystalline material fails is usually less then the predicted from calculated bond strengths in the crystal lattice because
the strength of failure is governed by crystal defects or crystal bond strength
the stress at failure is not reproducible experimentally
plastic deformation occurs before failure
it is, to date, impossible to calculate something as complicated as the stress at failure
Which of the following material properties is adversely affected by grain refinement ?
creep resistance
elastic module
Which of the following classes of materials exhibit a decreasing electrical conductivity with increasing temperature ?
metals
pure ionic materials
intrinsic semiconductors
p - type semiconductors
The property that characterizes a material's ability to be drawn into a wire is its
fatigue endurance limit
impact strength
Which of the following treatments will result in an increase in the fatigue strength of steel ?
short peening
surface roughening
In p - type semiconductors, conductivity is provided by
the motion of holes
the motion of electrons
the motion of ions
the motion of conductivity
A photon is
a particle of electromagnetic radiation
a neutral proton
a neutral electron
a charge neutron
Isotopes of an element are atomic species with
the same number of protons and electrons , but different numbers of neutrons
the same number electrons , but different numbers of neutrons and protons
the same number protons , but different numbers of neutrons and electons
the same number of valence electrons , but different numbers of protons, neutrons and non - valence electrons
The separation of isotopes of an elements always requires a physical, rather than chemical separation because
the differences in isotopes show up as difference in physical properties
the atomic mass, a physical characteristic, constitutes the difference between the isotopes
the electron configuration and, hence, chemical reactivity are the same
all of the above
The electronic configuration, 1s² 2s² 2p⁶ 3s² 3p⁵ is that of
a halogen
an alkali metal
an inert gas
a transition metal
An angstrom unit, commonly used for atomic and sub - atomic distances is equal to
10⁻¹⁰ m
10¹⁰ m
10⁻⁶ m
the distance light travels in 10⁻¹⁰ seconds
Which of the following statements about free carrier concentration associated with intrinsic semiconductors at room temperature is valid ?
it decreases with increasing values of energy gap
it increases with increasing values of energy gap
in increases with increasing carrier mobility
it decreases with increasing carrier mobility
At absolute zero temperature, all the valence electrons in an intrinsic semiconductor
are in the valence bond
are in the forbidden gap
are in the conduction bond
are free electrons
Carrier mobility depends on
temperature and the regularity of the crystal structure
resistivity
conductivity
charge per carrier
The movement of changers from an area of higher carrier concentration to an area of lower concentration is called
diffusion
gradient
mobility
recombination
Which term describes a material whose properties depend on the direction of stress
anisotropic
isotropic
endotropic
asymmetrical
Materials that emit light in the absence of high heat and continue to emit light after the energy source has been removed are called
phosphorescent
fluorescent
semiconductor - laser diodes
translucent diodes
A gamma ray is composed of
high energy electromagnetic radiation
high energy protons
high energy electrons
high energy neutrinos
Plank's constant represents
the ratio between the magnitude of a quantum of radiated energy and its frequency
the quantum or smallest amount of energy that can be emitted by radiation
the number of ergs in a kilogram calorie
the smallest number of any physical significance
The elements exhibit periodically recurring chemical and physical properties because
the properties are largely determined by the quantum numbers of the outer electrons, all of which except the first which indicates the orbit, recur in each orbit
they are arrange that way in the periodic table
the reason is unknown, it is simply observed experimentally
probability considerations dictate that properties will recur since there are limited number of possibilities
Which element about crystal dislocations is incorrect ?
dislocation in a crystalline lattice is located in an unexpected place
dislocations affect the tensile strength of a crystal
edge, screw and mixed dislocations are possible
dislocation is the defect caused by an atomic misalignment in a crystal
Ions are formed when
electrons are displaced from atoms or molecules by bombardment of high energy particles
a salt forms in an acid base neutralization reaction
salt crystal forms from the reaction of elemental sodium and chlorine
Which of the following statements about two crystalline forms of carbon, graphite and diamond is not correct ?
the properties of two crystals are, in fact, more similar than dissimilar
the diamond lattice is transparent to visible light, graphite is not
diamond is the hardest naturally occurring substance, graphite is soft
at high temperature diamond is a semiconductor, graphite is a conductor
Avogadro's number represents
the number of molecules in one gram mole of any compound
the number of molecules in one gram of any compound
the number of molecules in one liter of any gas at 1 atm pressure and 0°C
the number of valence electrons in a mole of any element
Aluminum hydroxide Al(OH)₃ is called an amphoteric hydroxide because
it can react as either an acid or a base
it has limited solubility in water
it contains 3 hydroxyl groups
either one, two or three hydroxyl group can ionize in water
Which of the following characteristics of the alkaline earth elements is unique
they are in group IIA of the periodic table
they have two "s" electrons in the outer orbit
they exhibit a valence of +2
they are found in soil
The chemical formula of the salt formed from the neutralization of potassium hydroxide and sulphuric acid is
K₂SO₄
NaCl
P₂SO₄
KSO₄
The chemical formula of the most common compound formed from beryllium and iodine is
BeI₂
Be₂I₇
BeI
Be₇I₂
Which of the following statements about the halogens is incorrect ?
they will react with water to form very strong bases
they are good oxidizing agents
they all exhibit a valence of -1
they form diatomic molecules
The group VIII elements, called the noble or rare gases, have the following properties
they do not react with other elements
they are rare
they are lighter than air
they remain gaseous down to just few degrees above absolute zero
Many transition metals exhibit more than one valence state in simple chemical reaction because
d electrons from one orbital down are not as reactive as the s electrons in the outer orbit
s and p electrons in the same orbit have very different reactivities
the valence state of metals change of the other elements in the molecule change
it is not always possible to predict how even simple reactions will occur
For this reaction, the equilibrium conditions are H₂ + I₂ = 2HI ΔH = -7.9 KJ
temperature and concentration
pressure, temperature and concentration
pressure only
temperature only
Ammonia is prepared by Haber's process N₂ + 3H₂ = 2NH₃ ΔH = -5.3 KJ In order to maximize the yield of ammonia, one can:
increase concentrations of hydrogen and nitrogen and decrease the temperature
increase concentrations of hydrogen and nitrogen and increase the temperature
decrease concentrations of hydrogen and nitrogen and increase the temperature
increase the concentrations of all the gases and increase the temperature
A close system experiences a reversible process where heat rejection is the only energy transfer. The entropy change
must be negative
must be zero
must be positive
is equal to the heat transfer
Consider an air - water vapor mixture similar to the atmosphere. If the dry bulb temperature equals the dew point temperature, the relative humidity will be
100 %
25 %
0 %
50 %
If the temperature of a medium is 0°C, what will be the temperature if it is doubled ?
273°C
0°C
524°R
460°R
The compression ignition cycle is modeled by which ideal cycle ?
diesel cycle
otto cycle
rankine cycle
brayton cycle
An ideal gas is contained in a rigid container. There is no work of a rotating shaft associated with the container. Any heat transfer is a function of
volume only
there cannot be any heat transfer
In a combustion chamber, fuel is burned to raise the temperature of the medium prior to production of work through an expansion process. The heat generated during the combustion reaction is the
heat of reaction
specific heat
heat of vaporization
heat of formation
There are many types of work associated with energy transfer across a boundary. One form of work is flow work which is described by all of the following except
it is associated with a closed system
it is the work which pushes mass in or out of a device
it is necessary to maintain a continuous flow
it is added to the internal energy to obtain enthalpy in the first law for a control volume
An open system First Law should be utilized for all of the following except
a piston - cylinder device
a nozzle
a turbine
a compressor
An insulated rigid container contains and ideal gas. The container is initially divided in half by a membrane such that one side is a vacuum and the other side contains the ideal gas. The membrane is broken and the gas fills the entire volume. All are true except
the temperature is quadrupled
the pressure is halved
the volume is doubled
the process is irreversible
An adiabatic process is characterized by which of the following ?
the heat transfer is zero
the entropy change is zero
the work is zero
it is reversible
A rigid container is heated by the sun. There is no shaft work associated with the container. From the First Law of Thermodynamics, you determine the resulting work to be
equal to zero
equal to the heat transter
equal to the volume times the change in pressure
equal to the change in internal energy
An inventor claims to have built and engineer which will revolutionize the automotive industry. Which of the following would be the best test to determine if the inventors claim is true ?
second law of thermodynamics
conservation of mass
first law of thermodynamics
zeroth law of thermodynamics
The isentropic efficiency is used to compare actual device such as turbines, compressors, nozzle and diffusers to ideal ones. Which statement is true
the inlet state and exit pressure are the same for both the ideal and actual device
only the ideal device is considered adiabatic
the ideal device operate irreversibly
the efficiency can be greater than one
The steam power cycle is modeled by the ideal cycle known as the
In an ideal refrigeration cycle, liquid leaves the condenser and is expanded in such a manner that the enthalpy of the resulting saturated mixture. This type of expansion is known as
throttling process
an isothermal process
a compression process
an isochoric process
In the case of regenerative gas turbine engine, which of the following is false ?
there is no heat rejected to the atmosphere in a regenerative gas turbine engine
the regenerator improves the efficiency of the engine
the exit temperature of the generator is higher than the inlet temperature of the compressor
if the generator is reversible, the effectiveness can approach 100 %
For an ideal turbojet, all of the following statements are true except
the work produced by the turbine is greater than the work required by the compressor
the process efficiency of the turbine is 100 %
the process efficiency of the compressor is 100 %
the process efficiency of the nozzle is 100 %
Which of the following statements about the carnot efficiency is not true ?
no reversible power cycles operating between two thermal reservoir can have an efficiency equal to the carnot efficiency
it depends only on the temperatures of the thermal reservoir
it can be used to determine if the cycle is possible or impossible
absolute temperature scales must be used when performing carnot efficiency calculation
Two independent intensive properties are required to fix the state of pure, simple compressible substance. People only attempt to fix the state of the medium using heat and work, which are not properties, which of the following statements about heat and work is not true ?
heat and work are point function
heat and work are transient phenomena
heat and work are forms of energy
heat and work are boundary phenomena
For steady, incompressible, inviscid flow, with no shaft and heat transfer, Bernoulli's equation can be written P/ρ + ½ v² + gz = constant. This form of equation is valid
for rotational flow, but only along streamlines
for irrotational flow, but only along streamlines
for rotational flow everywhere
for rotational flow, but only across streamlines
The simplified continuity equation ∇V = 0 is not valid for
steady compressible flow
steady incompressible flow
unsteady incompressible flow
steady rotational incompressible flow
How many electrons are there in the outermost octate of a chlorine atom ?
7
1
3
8
Heat transferred at constant volume process to the thermodynamic system of a fixed mass. The thermodynamic system will produce
zero work
small amount of work
negative work
positive work
Compressibility factor Z is a measure of the deviation of the actual gas behavior from ideal gas. An actual gas behavior may be assumed closed to the ideal gas when compressiblity factor Z approaches
1.0
0
0.5
0.75
Let's assume that the gas can be heated either at constant pressure or at constant volume process. The amount of heat Qp and Qv are transferred to the gas accordingly. If temperature increment per unit mass ΔT = constant, then
Qp is greater than Qv
Qp = Qv
Qp is less than Qv
Qp = Qv - ΔU
In manufacturing process 1000 KW of waste heat at temperature 327°C is available for utilization purposes. If the ambient temperature is 27°C, the designed heat engine producing 510 KW of net power will be
impossible
possible
irreversible
reversible
Which of the following instruments for measuring fluid velocity does not need to be calibrated ?
pitot static tube
orifice meter
venture tube
weir
Capillarity or the rise or fall of liquid in a thin tube is primarily controlled by which fluid property ?
surface tension
viscosity
density
temperature
A polytropic process is one in which the functional relationship between pressure and volume is given by PV ᴺ = constant with N value from -∞ to +∞ depending on the particular process. A constant volume process is represented by N equals
∞
zero
2
K
Cavitation in fluid mechanics refers to
a liquid to gaseous phase transition of the fluid due to low pressure
the oscillation of a plate due to turbulent fluctuations
the condensation of the vapor into liquid due to high pressure
the violation of the no slip condition on the wall
A large class of devices involve work. Assuming reversible steady state, steady flow process with negligible changes in kinetic and potential energy, the elementary work is
- Vdp
pdV
Vdp + pdV
Vdp - pdV
The reheat rankine cycle is proposed to decrease
moisture content in the low pressure stages of the turbine
mass flow rate of cooling water in the condenser
back pressure of the turbine
volumetric flow rate of the working fluid
In compressible fluid mechanics, a shock wave is considered normal shock wave when
the angle between the direction of flow and the wave is 90°
the shock wave occurs in air
the shock wave occurs at oblique angle to the flow
the flow remains supersonic on both sides of the shock wave
Which of the following statements defines best the capitalized cost ?
is the present worth of a specified uniform cash flow for an infinite analysis period
it is the initial cost of some equipment
it is the salvage value of an equipment
it is the amount of money equal to the cost minus benefit for an equipment
Which of the following is not taken into account in making an economic decision between two alternative equipment ?
reliability
operating cost
rate of return
salvage value
A heat sink will dissipate heat energy more rapidly if
its surface area is increased
its temperature is the same as the temperature of the surrounding air
it is covered by a material having a high thermal resistance
it is kept away from air current
A reference frame which remains fixed while fluid flows through is called
Eulerian
Lagrangian
Stokesian
A Navier - Stokes reference frame
For steady incompressible fully developed flow in a constant area pipe, friction along the walls of the pipe causes.
a reduction in static pressure along the length of the pipe
a reduction in mass flow rate along the length of pipe
a reduction of velocity along the length of pipe
an increase in the darcy friction factor along the length of the pipe
Select the answer which correctly ranks fluid meters from lowest to highest pressure loss
venturi tube, flow nozzle, thin plate orifice
venturi tube,thin plate orifice, flow nozzle
thin plate orifice, venturi tube, flow nozzle
flow nozzle, thin plate orifice, venturi tube
Identify which of the following problems for which the Moody chart would not be of use
flow in subsonic diffuser
flow of natural gas in long pipe
flow of oil in a long channel with square cross section
flow of water in a pipe at very high speed where the flow is extremely turbulent
Effective interest rate per year is defined as
the annual interest rate taking into account the effect of any compounding during the year
the nominal interest rate per year
the rate of return that can be realized from an investment
the interest rate per period times the number of periods per year
During inflationary time, which of the following statements best describes the best the loan payments of a fixed amount ?
future payments in year zero dollars are not constant in amount
future payments are worth more in year zero dollars
in actual dollars, the amount of future payments decreases
year zero dollars are worth less then future dollars
A pump is used to increase the pressure of water entering the boiler of steam power cycle. Which statement is true concerning the pump ?
the enthalpy of water leaving the pump is higher than the enthalpy of water entering the pump
the pump produces work
the pump has no effect on the cycle
the enthalpy is constant during the process
Which of the following is not a unit of pressure ?
kg / m²
Pa
bars
N / m²
Which of the following is the definition of Joule ?
N - m
a unit of power
kg - m / s²
rate of change of energy
Which of the following relations defines enthalpy ?
H = U + PV
H = U + P / T
H = U + P / V
H = PV + T
How is the quality x of a liquid vapor mixture defined ?
the fraction of the total mass that is saturated vapor
the fraction of the total volume that is saturated vapor
the fraction of total volume that is saturated liquid
the fraction of the total mass that is saturated liquid
What is the actual shape of the methane CH₄ molecule ?
a tetrahedral
linear
square planar
pyramidal
What is the oxidation state of the nitrogen in NO₃⁻ ?
+ 5
- 1
+ 3
+ 1
What is the oxidation number of Cr in the dicromate ion (Cr₂O₇) ²⁻
+ 6
Reactions generally proceed faster at higher temperature because of which of the following ?
the activation energy is less
the molecules are less energetic
the bonds are easier to break
the molecules collide more frequently
Determine the height of the centroid of the semi - circle with radius r from its diameter
4r / 3π
2r / 3
2πr /3
3r / 4π
What are valence electrons ?
the outer shell electrons
electrons with positive charge
the electrons of complete quantum shells
the K - quantum shell electrons
What is the strong bond between hydrogen atoms known as ?
ionic and metallic bond
What are Van der Waals forces ?
weak secondary bonds between atoms
primary bonds between atoms
forces between electrons and protons
forces present only in gases
Compare the metallic iron form Fe and the ferric ions Fe²⁺ and Fe³⁺. Which has the smallest atomic radius of the same temperature ?
Fe³⁺
Fe²⁺
Fe
they have the same radii
Polymers that favor crystallization are least likely to have which of the following
an atactic configuration of side group
small side group
only one repeating unit
small chain length
In general, what are the effects of cold working a metal ?
increase strength, decrease ductility
increase strength, increase ductility
decrease strength, decrease ductility
decrease strength, increase ductility
Which of the following is not structural class steel ?
tool and die
carbon
stainless
low - alloy
Which of the following phases of steel has face - centered cubic structure ?
austenite
ferrite
pearlite
martensite
The state of a thermodynamic system is always defined by its
properties
absolute temperature
process
temperature and pressure
Mathematically, a thermodynamic property is which of the following ?
a point function
a path function
an exact differential
discontinuous
The first law of thermodynamics states that
energy can neither be created nor destroyed
heat energy cannot be completely transformed into work
internal energy is due to molecular motion
entropy of the universe is increased by irreversible process
In terms of QH and QL, the network of a carnot cycle is
W = QH - QL
W = QH - QL / QL
W = QL / QH - QL
W = QL - QH
Is any non - quasistatic thermodynamic process, the over - all entropy of an isolated system will
increase only
decrease only
stay the same
decrease and then increase
Entropy is the measure of
randomness or disorder
the change in enthalpy of the system
the internal energy of the gas
the heat capacity of the substance
For spontaneously occurring natural process in an isolated system, which expression best express dS ?
dS is greater than 0
dS equals 0
dS is less than zero
dS = dQ / T
Energy changes are represented by all except
dQ rev / T
negative integral of VdP
mCpdT
TdS - PdV
Work or energy can be a function of all of the following except
force and time
force and distance
toque and angular acceleration
power and time
U + PV is a quantity called
enthalpy
flow energy
shaft work
entropy
In flow process, neglecting KE and PE changes, negative integral of Vdp represents
heat transfer
closed system work
Power may be expressed in units of
BTU / hr
ft - lbs
HP - hours
KW - hours
Equilibrium condition exist in all except which of the following ?
in steady state flow process
in reversible process
in process where driving forces are infinitesimals
where nothing can occur without an effect on the system's surroundings
Name the process that has no heat transfer
isentropic
isothermal
quasistatic
polytropic
An ideal gas ( k = 1.4 ) is expanded in a nozzle from Po = 1.5 MPa, To = 150°C, Vo = 0, to P₂ = 0.3 MPa. Assuming reversible adiabatic process the nozzle should be
convergent - divergent
diverging
converging
constant cross section
Enthalpy of an ideal gas is a function only of
pressure
internal energy
A small plastic bag is filled with moist air at 50% relative humidity, sealed and placed in an environmental chamber whose temperature and pressure may be independently varied. The relative humidity of the bag will lower under which of the following conditions
pressure is decreased
pressure is increased
temperature is decrease
temperature is decreased and pressure in increased
The rate of heat transfer through a given section of a uniform wall or a given temperature difference is
directly proportional to the thermal conductivity and inversely proportional to the thickness of the wall
directly proportional to the thermal conductivity and to the thickness of the wall
inversely proportional to the thermal conductivity and directly proportional thickness of the wall
inversely proportional to the thermal conductivity and to the thickness of the wall
Which of the following metals has the highest specific heat capacity at 100°C ?
aluminum
bismuth
copper
iron
The radical ion (NO₂)⁻ is called
nitrite
nitrate
nitride
binitrite
a sample of a substance to which chemical formula can be assigned, whose weight is equal to its formula weight is termed as
mole
molecule
gram equivalent weight
atom
The number of molecules in 22.4 L of a substance in its gaseous state is called
Avogadro's number
Dulong's number
Petit's number
Graham's number
Which of the following radioactive decay results in an increased Z or number of protons in the nucleus ?
negative beta decay ( electron emission )
alpha decay ( helium nucleus emission )
positive beta decay ( positron emission )
gamma emission ( photon energy emission )
The relationship between the extension of a spring and the force required to produce the extension is
F = kx
F = ma
F = μN
F = mv² / r
The deflection of beam is
inversely proportional to the modulus of elasticity and the moment of inertia
directly proportional to the modulus of elasticity and the moment of inertia
inversely proportional to the modulus of elasticity and the length of the beam cube
inversely proportional to the weight and length
Hard water is water which contains soluble salts of which of the following
calcium
sodium
sulfur
chlorine
A homogeneous round bar of diameter D, length L and total weight W is hung vertically from one end. If E is the modulus of elasticity, what is the total elongation of the bar ?
2WL / πD²E
WL / πD²E
WL / 2πD²E
WL / 2E
A thin walled pressurized vessel consist of a right circular cylinder with flat ends. Midway between the ends the stress is greatest in what direction ?
circumferential
longitudinal
radial
at an angle of 45° to the longitudinal and circumferential directions
The stress concentration factor
is the ratio of the maximum stress produced in a cross section to the allowable stress
is the ratio of the average stress produced in a cross section to the allowable stress
is the ratio of areas involved in the sudden change in cross section
cannot be evaluated for brittle material
Poisson's ratio is the ratio of
unit lateral deformation to the unit of longitudinal deformation
unit stress to unit strain
elastic limit to proportional limit
shear strain to compressive strain
The modulus of rigidity of a steel member is
defined as the unit shear stress divided by the unit shear deformation
a function of the length and depth
equal to the modulus of elasticity divided by one Poise
defined as the length divided by the moment of inertia
A thin homogeneous metallic plate containing a hole is heated sufficiently to cause expansion. If the coefficient of surface expansion is linear, the area of the hole will
increase at the same rate as the area of the metal increases
decrease at the same rate as the area of the metal increases
increase at twice the rate of the are of the metal increases
Hooke's law for an isotropic homogeneous medium experiencing one dimensional stress is
stress = E ⋅ strain
strain = E ⋅ stress
strain energy = E ⋅ internal energy
Force ⋅ area = E ⋅ change in length / length
The three moment equation may be used to analyze
continuous beam
beam loaded at the third point
a three element composite beam
a step tapered column
The area of the shear diagram of a beam between any two points on the beam is equal to the
change in the moment between the two points
change in the shear between the two points
total shear beyond the two points
average moment between the two points
Fixing both ends of a simply supported beam that has only a concentrated load at midspan will increase the allowed load by
no change
Young's modulus of elasticity for a material can be calculated indirectly form which of the following properties of material ?
density and velocity of sound in the material
temperature coefficient of expansion and dielectric constant
temperature coefficient of expansion and specific heat
density and interatomic spacing in the material
Modulus of resilience is
the measure of a materials ability to store strain energy
the same as the modulus of elasticity
the reciprocal of the modulus of elasticity
a measure of the deflection of a member
When a metal is cold worked, all of the following generally occur except
grains become equi - axed
ductility increases
tensile strength increases
recrystallization temperature decreases
Instrinsic silicon becomes extrinsically conductive, with electrons as majority carriers, when doped with
antimony
boron
germanium
Steel can be strengthened by the following except
quenching and tempering
work hardening
If 1080 steel ( 0.8 % wt C ) is annealed by very slow cooling from 1000°C to ambient temperature, its microstructure will consist of almost solely of
bainite
cementite
Which of the following is not a method of non destructive testing of steel castings and forgings ?
chemical analysis
radiography
magnetic particles
ultrasonic
Compressive strength of fully cured concrete is most directly related to
water - cement ratio
sand gravel ratio
fineness modulus
aggregate gradation
