Question 1
Question
What type of bond exists predominantly in sodium chloride crystal ?
Answer
-
ionic bond
-
metallic bond
-
covalent bond
-
polar bond
Question 2
Question
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
Question 3
Question
Which of the following leads to a reduction in the electrical resistivity of a pure metal ?
Question 4
Question
The rigidity of polymer can be increased by
Question 5
Question
Which of the following properties of a metal is insensitive to microstructure ?
Answer
-
modulus of elasticity
-
tensile strength
-
ductility
-
hardness
Question 6
Question
The dominant charge carriers in phosphorus - doped silicon crystal at room temperature are
Answer
-
electrons
-
electron holes
-
protons
-
silicon ions
Question 7
Question
Metals are conductive because
Answer
-
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
Question 8
Question 9
Question
An electron - volt is
Answer
-
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
Question 10
Question
Group IA are easily ionized because
Answer
-
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
Question 11
Question
The rare earth metals all have very similar chemical properties because :
Answer
-
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
Question 12
Question
Which of the following group of elements all form crystals of diamond structural lattice ?
Answer
-
carbon, silicon, germanium
-
carbon, boron, aluminum
-
carbon, cobalt, nickel
-
lithium, sodium, potassium
Question 13
Question
The stress or load where a crystalline material fails is usually less then the predicted from calculated bond strengths in the crystal lattice because
Answer
-
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
Question 14
Question
Which of the following material properties is adversely affected by grain refinement ?
Answer
-
creep resistance
-
tensile strength
-
ductility
-
elastic module
Question 15
Question
Which of the following classes of materials exhibit a decreasing electrical conductivity with increasing temperature ?
Answer
-
metals
-
pure ionic materials
-
intrinsic semiconductors
-
p - type semiconductors
Question 16
Question
The property that characterizes a material's ability to be drawn into a wire is its
Answer
-
ductility
-
tensile strength
-
fatigue endurance limit
-
impact strength
Question 17
Question
Which of the following treatments will result in an increase in the fatigue strength of steel ?
Answer
-
short peening
-
annealing
-
cold working
-
surface roughening
Question 18
Question
In p - type semiconductors, conductivity is provided by
Question 19
Question 20
Question
Isotopes of an element are atomic species with
Answer
-
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
Question 21
Question
The separation of isotopes of an elements always requires a physical, rather than chemical separation because
Answer
-
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
Question 22
Question
The electronic configuration, 1s² 2s² 2p⁶ 3s² 3p⁵ is that of
Answer
-
a halogen
-
an alkali metal
-
an inert gas
-
a transition metal
Question 23
Question
An angstrom unit, commonly used for atomic and sub - atomic distances is equal to
Question 24
Question
Which of the following statements about free carrier concentration associated with intrinsic semiconductors at room temperature is valid ?
Answer
-
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
Question 25
Question
At absolute zero temperature, all the valence electrons in an intrinsic semiconductor
Question 26
Question
Carrier mobility depends on
Question 27
Question
The movement of changers from an area of higher carrier concentration to an area of lower concentration is called
Answer
-
diffusion
-
gradient
-
mobility
-
recombination
Question 28
Question
Which term describes a material whose properties depend on the direction of stress
Answer
-
anisotropic
-
isotropic
-
endotropic
-
asymmetrical
Question 29
Question
Materials that emit light in the absence of high heat and continue to emit light after the energy source has been removed are called
Question 30
Question
A gamma ray is composed of
Question 31
Question
Plank's constant represents
Answer
-
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
Question 32
Question
The elements exhibit periodically recurring chemical and physical properties because
Answer
-
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
Question 33
Question
Which element about crystal dislocations is incorrect ?
Answer
-
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
Question 34
Question
Ions are formed when
Answer
-
all of these
-
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
Question 35
Question
Which of the following statements about two crystalline forms of carbon, graphite and diamond is not correct ?
Answer
-
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
Question 36
Question
Avogadro's number represents
Answer
-
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
Question 37
Question
Aluminum hydroxide Al(OH)₃ is called an amphoteric hydroxide because
Answer
-
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
Question 38
Question
Which of the following characteristics of the alkaline earth elements is unique
Answer
-
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
Question 39
Question
The chemical formula of the salt formed from the neutralization of potassium hydroxide and sulphuric acid is
Question 40
Question
The chemical formula of the most common compound formed from beryllium and iodine is
Question 41
Question
Which of the following statements about the halogens is incorrect ?
Answer
-
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
Question 42
Question
The group VIII elements, called the noble or rare gases, have the following properties
Answer
-
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
Question 43
Question
Many transition metals exhibit more than one valence state in simple chemical reaction because
Answer
-
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
Question 44
Question
For this reaction, the equilibrium conditions are
H₂ + I₂ = 2HI ΔH = -7.9 KJ
Question 45
Question
Ammonia is prepared by Haber's process
N₂ + 3H₂ = 2NH₃ ΔH = -5.3 KJ
In order to maximize the yield of ammonia, one can:
Answer
-
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
Question 46
Question
A close system experiences a reversible process where heat rejection is the only energy transfer. The entropy change
Question 47
Question
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
Question 48
Question
If the temperature of a medium is 0°C, what will be the temperature if it is doubled ?
Question 49
Question
The compression ignition cycle is modeled by which ideal cycle ?
Answer
-
diesel cycle
-
otto cycle
-
rankine cycle
-
brayton cycle
Question 50
Question
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
Question 51
Question
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
Answer
-
heat of reaction
-
specific heat
-
heat of vaporization
-
heat of formation
Question 52
Question
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
Answer
-
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
Question 53
Question
An open system First Law should be utilized for all of the following except
Question 54
Question
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
Question 55
Question
An adiabatic process is characterized by which of the following ?
Question 56
Question
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
Answer
-
equal to zero
-
equal to the heat transter
-
equal to the volume times the change in pressure
-
equal to the change in internal energy
Question 57
Question
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 ?
Answer
-
second law of thermodynamics
-
conservation of mass
-
first law of thermodynamics
-
zeroth law of thermodynamics
Question 58
Question
The isentropic efficiency is used to compare actual device such as turbines, compressors, nozzle and diffusers to ideal ones. Which statement is true
Answer
-
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
Question 59
Question
The steam power cycle is modeled by the ideal cycle known as the
Answer
-
rankine cycle
-
otto cycle
-
diesel cycle
-
brayton cycle
Question 60
Question
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
Answer
-
throttling process
-
an isothermal process
-
a compression process
-
an isochoric process
Question 61
Question
In the case of regenerative gas turbine engine, which of the following is false ?
Answer
-
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 %
Question 62
Question
For an ideal turbojet, all of the following statements are true except
Answer
-
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 %
Question 63
Question
Which of the following statements about the carnot efficiency is not true ?
Answer
-
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
Question 64
Question
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 ?
Answer
-
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
Question 65
Question
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
Answer
-
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
Question 66
Question
The simplified continuity equation ∇V = 0 is not valid for
Answer
-
steady compressible flow
-
steady incompressible flow
-
unsteady incompressible flow
-
steady rotational incompressible flow
Question 67
Question
How many electrons are there in the outermost octate of a chlorine atom ?
Question 68
Question
Heat transferred at constant volume process to the thermodynamic system of a fixed mass. The thermodynamic system will produce
Answer
-
zero work
-
small amount of work
-
negative work
-
positive work
Question 69
Question
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
Question 70
Question
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
Answer
-
Qp is greater than Qv
-
Qp = Qv
-
Qp is less than Qv
-
Qp = Qv - ΔU
Question 71
Question
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
Answer
-
impossible
-
possible
-
irreversible
-
reversible
Question 72
Question
Which of the following instruments for measuring fluid velocity does not need to be calibrated ?
Answer
-
pitot static tube
-
orifice meter
-
venture tube
-
weir
Question 73
Question
Capillarity or the rise or fall of liquid in a thin tube is primarily controlled by which fluid property ?
Answer
-
surface tension
-
viscosity
-
density
-
temperature
Question 74
Question
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
Question 75
Question
Cavitation in fluid mechanics refers to
Answer
-
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
Question 76
Question
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
Answer
-
- Vdp
-
pdV
-
Vdp + pdV
-
Vdp - pdV
Question 77
Question
The reheat rankine cycle is proposed to decrease
Answer
-
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
Question 78
Question
In compressible fluid mechanics, a shock wave is considered normal shock wave when
Answer
-
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
Question 79
Question
Which of the following statements defines best the capitalized cost ?
Answer
-
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
Question 80
Question
Which of the following is not taken into account in making an economic decision between two alternative equipment ?
Answer
-
reliability
-
operating cost
-
rate of return
-
salvage value
Question 81
Question
A heat sink will dissipate heat energy more rapidly if
Answer
-
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
Question 82
Question
A reference frame which remains fixed while fluid flows through is called
Question 83
Question
For steady incompressible fully developed flow in a constant area pipe, friction along the walls of the pipe causes.
Answer
-
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
Question 84
Question
Select the answer which correctly ranks fluid meters from lowest to highest pressure loss
Answer
-
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
Question 85
Question
Identify which of the following problems for which the Moody chart would not be of use
Answer
-
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
Question 86
Question
Effective interest rate per year is defined as
Answer
-
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
Question 87
Question
During inflationary time, which of the following statements best describes the best the loan payments of a fixed amount ?
Answer
-
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
Question 88
Question
A pump is used to increase the pressure of water entering the boiler of steam power cycle. Which statement is true concerning the pump ?
Answer
-
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
Question 89
Question
Which of the following is not a unit of pressure ?
Question 90
Question
Which of the following is the definition of Joule ?
Answer
-
N - m
-
a unit of power
-
kg - m / s²
-
rate of change of energy
Question 91
Question
Which of the following relations defines enthalpy ?
Answer
-
H = U + PV
-
H = U + P / T
-
H = U + P / V
-
H = PV + T
Question 92
Question
How is the quality x of a liquid vapor mixture defined ?
Answer
-
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
Question 93
Question
What is the actual shape of the methane CH₄ molecule ?
Answer
-
a tetrahedral
-
linear
-
square planar
-
pyramidal
Question 94
Question
What is the oxidation state of the nitrogen in NO₃⁻ ?
Question 95
Question
What is the oxidation number of Cr in the dicromate ion (Cr₂O₇) ²⁻
Question 96
Question
Reactions generally proceed faster at higher temperature because of which of the following ?
Answer
-
the activation energy is less
-
the molecules are less energetic
-
the bonds are easier to break
-
the molecules collide more frequently
Question 97
Question
Determine the height of the centroid of the semi - circle with radius r from its diameter
Answer
-
4r / 3π
-
2r / 3
-
2πr /3
-
3r / 4π
Question 98
Question
What are valence electrons ?
Answer
-
the outer shell electrons
-
electrons with positive charge
-
the electrons of complete quantum shells
-
the K - quantum shell electrons
Question 99
Question
What is the strong bond between hydrogen atoms known as ?
Answer
-
covalent bond
-
ionic bond
-
metallic bond
-
ionic and metallic bond
Question 100
Question
What are Van der Waals forces ?
Answer
-
weak secondary bonds between atoms
-
primary bonds between atoms
-
forces between electrons and protons
-
forces present only in gases
Question 101
Question
Compare the metallic iron form Fe and the ferric ions Fe²⁺ and Fe³⁺. Which has the smallest atomic radius of the same temperature ?
Answer
-
Fe³⁺
-
Fe²⁺
-
Fe
-
they have the same radii
Question 102
Question
Polymers that favor crystallization are least likely to have which of the following
Question 103
Question
In general, what are the effects of cold working a metal ?
Answer
-
increase strength, decrease ductility
-
increase strength, increase ductility
-
decrease strength, decrease ductility
-
decrease strength, increase ductility
Question 104
Question
Which of the following is not structural class steel ?
Answer
-
tool and die
-
carbon
-
stainless
-
low - alloy
Question 105
Question
Which of the following phases of steel has face - centered cubic structure ?
Answer
-
austenite
-
ferrite
-
pearlite
-
martensite
Question 106
Question
The state of a thermodynamic system is always defined by its
Answer
-
properties
-
absolute temperature
-
process
-
temperature and pressure
Question 107
Question
Mathematically, a thermodynamic property is which of the following ?
Answer
-
a point function
-
a path function
-
an exact differential
-
discontinuous
Question 108
Question
The first law of thermodynamics states that
Answer
-
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
Question 109
Question
In terms of QH and QL, the network of a carnot cycle is
Answer
-
W = QH - QL
-
W = QH - QL / QL
-
W = QL / QH - QL
-
W = QL - QH
Question 110
Question
Is any non - quasistatic thermodynamic process, the over - all entropy of an isolated system will
Question 111
Question
Entropy is the measure of
Answer
-
randomness or disorder
-
the change in enthalpy of the system
-
the internal energy of the gas
-
the heat capacity of the substance
Question 112
Question
For spontaneously occurring natural process in an isolated system, which expression best express dS ?
Answer
-
dS is greater than 0
-
dS equals 0
-
dS is less than zero
-
dS = dQ / T
Question 113
Question
Energy changes are represented by all except
Answer
-
dQ rev / T
-
negative integral of VdP
-
mCpdT
-
TdS - PdV
Question 114
Question
Work or energy can be a function of all of the following except
Question 115
Question
U + PV is a quantity called
Answer
-
enthalpy
-
flow energy
-
shaft work
-
entropy
Question 116
Question
In flow process, neglecting KE and PE changes, negative integral of Vdp represents
Answer
-
shaft work
-
heat transfer
-
closed system work
-
flow energy
Question 117
Question
Power may be expressed in units of
Answer
-
BTU / hr
-
ft - lbs
-
HP - hours
-
KW - hours
Question 118
Question
Equilibrium condition exist in all except which of the following ?
Answer
-
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
Question 119
Question
Name the process that has no heat transfer
Answer
-
isentropic
-
isothermal
-
quasistatic
-
polytropic
Question 120
Question
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
Answer
-
convergent - divergent
-
diverging
-
converging
-
constant cross section
Question 121
Question
Enthalpy of an ideal gas is a function only of
Answer
-
temperature
-
entropy
-
pressure
-
internal energy
Question 122
Question
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
Question 123
Question
The rate of heat transfer through a given section of a uniform wall or a given temperature difference is
Answer
-
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
Question 124
Question
Which of the following metals has the highest specific heat capacity at 100°C ?
Answer
-
aluminum
-
bismuth
-
copper
-
iron
Question 125
Question
The radical ion (NO₂)⁻ is called
Answer
-
nitrite
-
nitrate
-
nitride
-
binitrite
Question 126
Question
a sample of a substance to which chemical formula can be assigned, whose weight is equal to its formula weight is termed as
Answer
-
mole
-
molecule
-
gram equivalent weight
-
atom
Question 127
Question
The number of molecules in 22.4 L of a substance in its gaseous state is called
Answer
-
Avogadro's number
-
Dulong's number
-
Petit's number
-
Graham's number
Question 128
Question
Which of the following radioactive decay results in an increased Z or number of protons in the nucleus ?
Answer
-
negative beta decay ( electron emission )
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alpha decay ( helium nucleus emission )
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positive beta decay ( positron emission )
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gamma emission ( photon energy emission )
Question 129
Question
The relationship between the extension of a spring and the force required to produce the extension is
Answer
-
F = kx
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F = ma
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F = μN
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F = mv² / r
Question 130
Question
The deflection of beam is
Answer
-
inversely proportional to the modulus of elasticity and the moment of inertia
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directly proportional to the modulus of elasticity and the moment of inertia
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inversely proportional to the modulus of elasticity and the length of the beam cube
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inversely proportional to the weight and length
Question 131
Question
Hard water is water which contains soluble salts of which of the following
Answer
-
calcium
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sodium
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sulfur
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chlorine
Question 132
Question
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 ?
Answer
-
2WL / πD²E
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WL / πD²E
-
WL / 2πD²E
-
WL / 2E
Question 133
Question
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 ?
Question 134
Question
The stress concentration factor
Answer
-
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
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is the ratio of areas involved in the sudden change in cross section
-
cannot be evaluated for brittle material
Question 135
Question
Poisson's ratio is the ratio of
Answer
-
unit lateral deformation to the unit of longitudinal deformation
-
unit stress to unit strain
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elastic limit to proportional limit
-
shear strain to compressive strain
Question 136
Question
The modulus of rigidity of a steel member is
Answer
-
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
Question 137
Question
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
Answer
-
increase at the same rate as the area of the metal increases
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decrease at the same rate as the area of the metal increases
-
stay the same
-
increase at twice the rate of the are of the metal increases
Question 138
Question
Hooke's law for an isotropic homogeneous medium experiencing one dimensional stress is
Question 139
Question
The three moment equation may be used to analyze
Question 140
Question
The area of the shear diagram of a beam between any two points on the beam is equal to the
Answer
-
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
Question 141
Question
Fixing both ends of a simply supported beam that has only a concentrated load at midspan will increase the allowed load by
Answer
-
100 %
-
50 %
-
25 %
-
no change
Question 142
Question
Young's modulus of elasticity for a material can be calculated indirectly form which of the following properties of material ?
Answer
-
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
Question 143
Question
Modulus of resilience is
Answer
-
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
Question 144
Question
When a metal is cold worked, all of the following generally occur except
Answer
-
grains become equi - axed
-
ductility increases
-
tensile strength increases
-
recrystallization temperature decreases
Question 145
Question
Instrinsic silicon becomes extrinsically conductive, with electrons as majority carriers, when doped with
Answer
-
antimony
-
boron
-
germanium
-
aluminum
Question 146
Question
Steel can be strengthened by the following except
Answer
-
annealing
-
quenching and tempering
-
work hardening
-
grain refinement
Question 147
Question
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
Answer
-
pearlite
-
austenite
-
bainite
-
cementite
Question 148
Question
Which of the following is not a method of non destructive testing of steel castings and forgings ?
Answer
-
chemical analysis
-
radiography
-
magnetic particles
-
ultrasonic
Question 149
Question
Compressive strength of fully cured concrete is most directly related to
Answer
-
water - cement ratio
-
sand gravel ratio
-
fineness modulus
-
aggregate gradation