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WorksheetsDay 10 p. 71-79
Total questions: 93
Worksheet time: 1hrs 7mins
A Carnot operates between two reservoirs. One reservoir is at a higher temperature, TH, and the other is a cooler is a cooler temperature, TC. What is the coefficient of performance, COP, of the refrigerator?
TH / TC
TH – TC/TH
1 – TC/TH
TC / (TH-TC)
All of the following processes strengthen metals, EXCEPT:
Annealing above the recrystallization temperature
Work hardening by mechanical deformation below the recrystallization temperature (cold working)
Heat treatment such as quenching and tempering, for production of a finer microstructure
Precipitation processes, such as age hardening, which produce high strength by formation of sub microscopic phases during low temperature heat treatment
The valence hand model used to explain metallic conduction is based on all the following statements, EXCEPT:
Each valence band may contain up to 2n electrons/n atom: each electron lies at a discretely different level
Fermi energy level, Ef, is essentially temperature independent, and is the energy at which 50% of available energy states are occupied
A conduction bad lies at the next higher set of electronic energy levels above those occupied at the ground state
Conduction occurs when an electron remains in its existent valence band
Intrinsic silicon becomes extrinsically conductive with electrons as majority carriers, when doped with which of the following?
nothing
antimony
boron
germanium
Which of the following is standard temperature and pressure (STP)?
0 K and one atmosphere pressure
32 °F and zero pressure
0 °F and zero pressure
0 °C and one atmosphere pressure
When the emitter to base of an npn transistor is forward biased, and base to collector is reverse biased, all of the following are correct EXCEPT:
Electrons are majority carries in the n – emitter and n – collector regions
Electrons are minority carries in the p – base region
Holes are majority carries in the p – base region
The emitter is positive with respect to the collector
All of the following statements about solid solution are correct, EXCEPT:
Solid solutions can result when basic structure of the solvent can accommodate solute additions
In solid solution larger solute atoms occupy the interstitial space between solvent atoms that are located at the lattice sites
Solid solutions may result by substitution of one atomic species for another, provided radii and electronic structure are compatible
Order – disorder transitions that occur at elevated temperature in solid solutions involve changes due to thermal agitation from preferred orientation to random occupancy of lattice sites
All of the following statements about ferromagnetism are correct EXCEPT:
Magnetic domains are small volumes existent within a single crystal where atomic magnetic moments are unidirectionally aligned
Domains are randomly oriented when unmagnetized. On magnetization, domains oriented with the external field grow at the expense of unaligned domains
Impurities, inclusions and strain hardening interfere with change of domain boundaries, and add to the permanency of a magnet
High magnetic susceptibility of ferromagnetic materials disappears below the Curie temperature
All of the following statements about steels are correct, EXCEPT:
Yield strength of commercially available heat treated alloy steels does not exceed 200,000 psi
High temperature alloys used in jet engine turbine blades can withstand 2000°F continuously over extended period
Intergranular corrosion of chromium – nickel stainless steels is reduced when stabilized by addition of columbium (niobium), titanium or tantalum to preferentially form carbides and prevent chromium depletion and chromium carbide precipitation is grain boundary areas
Abrasion resistance of extra strength steels may be obtained by increasing hardness to 225 – 400 Brinell at the expense of some ductility and toughness
Steels can be strengthened by all of the following practices, EXCEPT:
annealing
work hardening
quenching and tempering
grain refinement
All of the following statements about the austenite – martensite – bainite transformation in steel are correct, EXCEPT:
Martensite is fine grained alpha-ferrite, supersaturated with carbon, in a metastable body centered tetragonal structure. It forms by shear (slippage) during the rapid quench of face centered cubic austenite ( - ferrite)
Martensite is strong and hard, but brittle, Tampering toughens it and reduces brittleness
Tempering of martensite is done by judicious reheating to produce, by diffusion, a fine – grained tough, strong microstructures
Bainite and tempered martensite have distinctively different microstructures
All of the following statements about mechanical failure are true, EXCEPT:
Brittle fracture occurs with little plastic deformation and relatively small energy absorption
Ductile fracture is characterized by significant amounts of energy absorption and plastic deformation (evidenced by elongation and reduction in cross-sectional area)
Ductile – brittle transition in failure mode occurs at reduced temperatures for most materials, because fracture strength remains constant with temperature while yield strength increases as temperature is reduced. At high temperatures yield strength is least; at low temperatures fracture strength is least
Fatigue failure due to cyclic stress frequency dependent
All of the following statements about rusting of iron are correct, EXCEPT:
Contact with water, and oxygen are necessary for fursting to occur
Contact with a more electropositive metal reduces rusting
Halides aggravate rusting, a process which involves electrochemical oxidation-reduction reactions
Pitting occurs in oxygen – rich anodic areas, and the rust is deposited nearby
Which statement about area moments of inertia is false?
I = ∫ d^2 (dA)
The area moment of inertia arises whenever the magnitude of the surface forces varies linearly with distance
The moment of inertia of a large area is equal to the summation of the inertia of the smaller areas within the larger area
The area closest to the axis of interest are the most significant
Which of the following affects most of the electrical and thermal properties of materials?
the atomic weight expressed in grams per gram-atom
the electrons, particularly the outermost ones
the magnitude of electrical charge of the protons
the weight of the atoms
Which of the following is not a method of non-destructive testing of steel casting and forgings?
radiography
magnetic particle
ultrasonic
chemical analysis
Compressive strength of fully cured concrete is most directly related to:
sand-gravel
water-cement ratio
aggregate gradation
absolute volume of cement
According to the ACI code, the modular ratio, n, of structural concrete with a 28 – day ultimate compressive strength, fc, of 3000 is nearest to
7
8
9
10
What are valence electrons?
the outershell electrons
electrons with positive charge
the electrons of the complete quantum shells
the K-quantum shell electrons
What is the strong bond between hydrogen atoms known as?
the ionic bond
ionic and metallic bond
the metallic bond
the covalent bond
What are Van der Waals forces?
weak secondary bonds between atoms
primary bonds between atoms
forces between electrons and protons
forces not present in liquids
All of the following statements about air entrained concrete are correct, EXCEPT:
Air entrained is recommended when concrete is exposed to severe frost action
With air entrainment, the quantity of water to produce a given consistency (slump) is reduced
With air entrainment, the quantity of water to produce a specified 28 day compressive strength is reduced
Air entrainment reduces resistance to the freeze – that that occurs when salt is used to melt ice or snow
In the design of a reinforced concrete structure, tensile strength of the concrete is normally
Assumed to be 1/10 of the 28-day compressive strength
Determined by beam tests
Neglected
Assumed to be 200 psi
All of the following groups of plastics are thermoplastic, EXCEPT:
Polyvinylchloride (PVS) and polyvinyl acetate
Polyethylene, polypropylene, and polysterene
Tetrafluorothylene (Teflon) and other fluorocarbons
Phenolics, melamine and epoxy
Compare the metallic iron atom Fe and the ferric ions Fe^3+ and Fe^3+. Which has the smallest atomic radius? (Assume all are at the same temperature)
Fe
Fe^2+
Fe^3+
They have the same radii
Cesium (Cs) and sodium (Na) both have the same valence (+1), yet with chlorine (Cl), cesium has a coordination number of 8 in CsCl, while sodium has a coordination number of only 6 in NaCl. What is the main reason for this difference?
The atomic weight of Cs is larger
Cs contains more electrons than the weight of Na
Cs forms covalent bonds in CaCl
Cs is too large to be coordinated by only 6 chloride ions
Which of the following statements is false?
Ceramics are inorganic, nonmetallic solids that are processed or used at high temperature
Metals are chemical elements that form substances that are opaque, lustrous, and good conductors of heat and electricity.
Oxides, carbides, and nitrides are considered to be within the class of materials known as glasses
Most metals are strong, ductile, and malleable. In general, they are heavier than most other substances
Kinematic viscosity may be expressed as:
ft^2 / sec
sec^2 / ft
slug sec^2 / ft
slugs / sec
Absolute viscosity of a fluid varies with pressure and temperature and is defined as a function of
Density and angular deformation rate
Density, shear stress and angular deformation rate
Density and shear stress
Shear stress and angular deformation rate
Total energy of a compressible or incompressible fluid flowing across any section in a pipeline is a function of:
pressure and velocity
pressure, density, and velocity
flow energy, kinetic energy, height above datum, and internal energy
pressure density, velocity and height above datum
Which of the following is not a viscoelastic material?
plastic
metal
rubber
glass
In molecules of the same composition, what are the variations of atomic arrangements known as?
polyemers
isomers
monomers
crystal system
Which of the following accurately describes differences between crystalline polymers and simple crystals?
I. Crystalline polymers are made of folded chains of atoms unlike simple crystals
II. Crystal size can be increased by raising the crystallization temperature only in polymers
III. While a simple crystal may be totally crystallized, a polymer can reach only partial crystallization
Polymers that favor crystallization are least likely to have which of the following?
small side groups
only one repeating unit
an atactic configuration of side groups
small chain lengths
The locus of the elevations to which water will rise in a piezometer tube is termed:
stagnation pressure
the enegy gradient
the hydraulic gradient
friction head
Which of the following statements most nearly approximates condition in turbulent flow?
Fluid particles move along smooth, straight paths
Energy loss varies linearly with velocity
Energy loss varies as the square of the velocity
Newton’s law of viscosity governs the flow
For turbulent flow of a fluid in a pipe, all of the following are true EXCEPT:
The average velocity will be nearly the same as at the pipe center
Energy lost due to turbulence and friction varies with kinetic energy
Pipe toughness affects the friction factor
Reynolds number will be less than 2000
In fluid flow, if the fluid travels parallel to the adjacent layers and the paths of individual particles do not cross, the flow is said to be:
laminar
turbulent
critical
dynamic
Flow nets are drawn to show all of the following EXCEPT:
Streamlines spaced to bound streamtubes of equal volume flow rate, q
Flow and pressure drops in distribution systems
Paths of particles in 2-and 3-dimensional flow
Equipotential lines perpendicular to streamlines
Which of the following constitutes a group of parameters with the dimensions of power?
ρ A V
DV ρ / μ
PAv
ρv^2 / P
Which of the following constitutes a group of parameters with the dimensions of power?
ρ A V
DV ρ / μ
PAv
ρv^2 / P
At or below critical velocity in small pipes or at very low velocities, the loss of head due to friction
varies directly as velocity
can be ignored
is infinitely large
varies as the velocity squared
At constant pressure P all of the following statements about low rate, q in turbulent flow in a pipe are true, EXCEPT:
q varies approximately as (diameter, D)^2
q decreases as pipe surface roughness ratio, ∈/D increases
q varies as (velocity, V)^2
q decreases inversely as (fluid density, ρ)^1/2
What is the atomic packing factor for a simple cubic crystal?
0.48
0.52
1.00
1.05
Which of the following statements is false?
Both copper and aluminum have a face-centered crystal structure
Both magnesium and zinc have a hexagonal close-packed crystal structure
Iron can have either a face-centered or a body-centered cubic crystal structure
Both lead and cadmium have a hexagonal close-packed crystal structure
Which of the following statements is false?
The coordinates of the unique lattice points for a body-centered cubic unit cell are: 0, 0, 0 and 1/2, 1/2, 1/2.
The coordinates of the unique lattice points for a face-centered cubic unit cell are: 0, 0, 0; 1/2, 1/2, 0, 1/2, 0, 1/2; and 0, 1/2, 1/2.
The coordinates of the unique lattice points for a simple cubic unit cell are 0, 0, 0.
The coordinates of the unique lattice points for a rhombohedral unit cell are 1/2, 1/2, 1/2.
Which crystal structure possesses the highest number of close-packed planes and close-packed direction?
simple cubic
body-centered cubic
face-centered cubic
close-packed hexagonal
What are the most common slip planes for face-centered cubic and body-centered cubic structures, respectively?
face-centered: (111), body-centered: (110)
face-centered: (100), body-centered: (110)
face-centered: (110), body-centered: (111)
face-centered: (111), body-centered: (100)
Entrance losses between tank and pipe, or losses through elbows, fittings and valves are generally expressed as functions of
kinetic energy
pipe diameter
friction factor
volume flow rate
The vena contracta of a sharp hydraulic orifice usually occurs:
At the geometric center of the orifice
At a distance of about 10% of the orifice diameter upstream from the plane of the orifice
At a distance equal to about two orifice diameters downstream from the plane of the office
At a distance equal to about one-half the orifice diameter downstream from the plane of the orifice
Modes of extinguishing obligations when an auditor abandons his right to collect:
condonation
forfeiture
debt cancellation
liquidated damages
With regard to corrosion of metals, passivation is the process that:
intensifies deterioration temporarily
inhibits further deterioration
changes the composition of the metal
alter the grain size of the metal
Cavitation is the result of
static pressure in a fluid becoming less than fluid vapor pressure
rivets under load impact
exposure of concrete to salt water
heat treatment of a low carbon steel
On doubling the speed, N, of a centrifugal pump, all of the following are true, EXCEPT:
Head, H is increased by a factor of 4
Horsepower, P is increased by a factor of 8
Head, horsepower and volume flow rate are independently variable
Volume flow rate, Q is increased by a factor of 2
The first law of thermodynamics states that:
heat energy cannot be completely transformed into work
internal energy is due to molecular motion
heat can only be transferred from a body of higher temperature to one of lower temperature
energy can be neither created nor destroyed
In any non – quasistatic thermodynamics process, the overall entropy of an isolated system will:
increase then decrease
stay the same
decrease and then increase
increase only
Comparing the face-centered cubic lattice with the hexagonal close-packed lattice, which of the following features describes the hexagonal close-packed structure only?
It has the closes packed lattice structure
Its coordination number is 2
Its deformation properties are more directional
Its stacking order is ABCABC
A plane intercepts the coordinate axis at x = 1, y = 1, and z = 2. What are the Miller indices of the plane?
(132)
(123)
(623)
(326)
Entropy is a measure of
the change in enthalpy of a system
the internal energy of a gas
the heat capacity of a substance
randomness or disorder
What is the degree of the polynomial 3x^4y + 2x^3z^3 - 4yz^2?
6th
5th
4th
3rd
For a complex number a + bi, the real number √(a^2 + b^2) is of the complex number.
absolute value
magnitude
modulus
all of the above
In the quadratic equation Ax^2 + Bx + C = 0, when the two roots are multiplied, the result is
C/A
-B/A
-C/A
A/C
What is the discriminant of the quadratic equation Ax^2 + Bx + C = 0?
√(B^2 - 4AC)
B^2 - 4AC
B^2 + 4AC
√(B^2 + 4AC)
What is the multiplicative inverse of a + bi?
0
1
-a - bi
a/(a^2 + b^2) - bi/(a^2 + b^2)
Equations used for checking the solution to a plane triangle using law of sine’s are as follows:
C/A
-B/A
-C/A
A/C
The equation y^2 = (x^2 + 1)^2(2 - x^2)^2 is an equation of
cocked hat
fishmouth
spiral
lemniscate
The equation (x^2 + 2ay - a^2) = y^2(a^2 - x^2) is a
rosette
cocked hat
fishmouth
spiral
The equation x^2 + y^2 = a^2 is a
cocked hat
fishmouth
triscectrix
lames quartic
The equation 푥^2 + 푦^2 = 푎^2 is a
cocked hat
fishmouth
triscectrix
lames quartic
What is the graph of the equation 퐴푥^2 + 퐵푥 + 퐶푦^2 + 퐷푦 + 퐸푥 + 퐹 = 0?
Circle
Ellipse
Parabola
Hyperbola
The semi-conjugate axis of the hyperbola 푥^2 – 푦^2 = 1
3
-3
-2
2
The length of the latus rectum of the parabola 푦 = 4푝푥^2 is
4p
2p
4p
2p
The equation 푎푥^2 = 푦^2(2푎 − 푦) is the equation of
the top
cocked hat
fishmouth
lames quartic
The equation (푥^2 + 푦^2)^2 = 푎푥^2푦 is an equation of
bifolium
cocked hat
spiral
limacon
A line parallel to the y-axis at a directed distance 푥1 has the equation
푦 = 푦1
푥 = 푥1
푦 = 푥1
푥 = 푦1
Let 푚1 and 푚2 be the respective slopes of two perpendicular lines. Then
푚1 + 푚2 = 1
푚1 + 푚2 = 0
(푚1)(푚2) = 1
(푚1)(푚2) = −1
In general equation of a conic section 퐴푥^2 + 퐵푥푦 + 퐶푦^2 + 퐷푥 + 퐸푦 + 퐹 = 0, if A and C have different signs, then the curve is a/an
What is 1 – 푡푎푛 ℎ^2 푥 equal to?
푠푒푐 ℎ^2 푥
푐표푠 ℎ^2 푥
푐표푡 ℎ^2 푥
푐푠푐 ℎ^2 푥
The integral of 푠푖푛^m 휃 푐표푠^n 휃 푑휃 can easily be determined by using Wallis formula provided the limits are form
0 to π
0 to π/2
0 to π/4
0 to 2π
The derivative of 푎^푢 with respect to x is
푎^푢 ln 푎 d푢/dx
푎^푢 ln 푢 d푢/dx
푢^푎 ln 푎 d푢/dx
푢^푎 ln 푢 d푢/dx
The quantity 2/(푒^푥 – 푒^−푥) is equal to
cosh x
tanh x
csch x
sech x
The value of x in trigonometric substitution with an integrand involving (푎^2 – 푥^2) is
a sec θ
a tan θ
a cos θ
a sin θ
An infinite series in which successive terms are of the form of constant times successive integral power of the variable. It takes the form of 푎0 + 푎1푥 + 푎2푥^2 + 푎3푥^3 + ... .
Fourier series
Taylor’s series
McClaurin series
Power series
How can the differential equation a d^2x/dt^2 + B(t) dx/dt + C = D(t) best described?
linear, homogeneous, and first order
homogeneous and first order
linear, second order, and nonhomogeneous
linear, homogeneous and second order
The differential equation given is correctly described by which one of the following choices?
In finding the distance, d, between two points, which equation is the appropriate one to use?
Linear, second order, homogeneous
Nonlinear, second order, homogeneous
Linear, second order, non homogeneous
Nonlinear, second order, nonhomogeneous
Energy changes are represented by all EXCEPT which one of the following?
The expression 3!0! is equal to
∞
2!
120
0
Which of the statements is true concerning the following continuity equation?
Under certain flow conditions, the expression for the first law of thermodynamics for a control volume reduces to Bernoulli’s equation:
The compressibility factor, z, is used for predicting the behavior of non-ideal gases. How is the compressibility factor defined relative to an ideal gas?
Given that a is a lattice constant that h, k, and I are the Miller indices, which of the following equations describes the interplanar distance d in a cubic crystal?
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?
