問題一覧
1
In a crystal structure, what is an interstitial atom?
an extra atom sitting at a nonlattice point
2
The ease with which dislocations are able to move through a crystal under stress accounts for which of the following? I. ductility II. lower yield strength III. hardness
I and II
3
What does the Charpy impact test measure? I. the energy required to break a test sample Il. the strength of a test sample III. the ductile to brittle transition temperature of metals
I and III
4
As the amount of slip increases, additional deformation becomes more difficult and decreases until the plastic flow finally stops. Slip may begin again only if a larger stress is applied. What is this phenomenon known as?
strain hardening
5
Which of the following is FALSE? (A) Grain size is of minor importance in considering the properties of polycrystalline materials. (B) Fine-grained materials usually exhibit greater yield stresses than coarse. grained materials at low temperatures. (C) At high temperatures, grain boundaries become weak, and sliding occurs. (D) Grain boundary sliding is the relative movement of two grains by a shear movement parallel to the grain boundary between them.
A
6
Which of the following docs cold working a metal cause?
elongation of grains in the flow direction, an increase in dislocation density, and an overall increase in energy of the metal
7
In a queueing process of customers in a store, what type of distribution most likely governs the time between consecutive arrivals of customers?
an exponential distribution
8
As the simplex algorithm progresses from one solution to the next in a linear programming maximization problem, what will happen to the value of the objective function?
It will increase or stay the same.
9
If an integer programming problem is solved as a linear programming problem and the resulting values of the decision variable are rounded off, which of the following will result?
an integer solution that may be optimum, or close to it
10
Which of the following are true statements about the modulus of elasticity, E?
It is the slope of the stress-strain diagram in the linearly elastic region.
11
Which of the following is NOT an important criterion for forming a complete binary solid solution? (A) The difference in radii should be less than 15%. (B) The constituent elements must have the same crystal structure. (C) The atoms should be close to one another in the periodic table. (D) The difference in atomic numbers should be small.
D
12
A concave opherical mirror has a focal length of 12 cm. If an object 16 placed 6 cm in front of it, the image position is:
12 cm in front of the mirror
13
The allowable tensile stress for a 6.25 mm diameter bolt with a thread length of 5.5 mm is 207 MPa. The allowable shear stress of the material is 103 MPa. Where and how will such a bolt be most likely to fail if placed in tension? (Assume threads are perfectly triangular and that the force is carried at the mean thread height.)
at the threads due to shear
14
Which of the following statements is FALSE?
Addition of small amounts of silicon to steel can cause a marked decrease in yield strength of the steel.
15
What is transformed in a eutectoid reaction? (A) One liquid is transformed into two solids of different composition. (B) A solid becomes a liquid at the eutectic temperature. (C) A liquid becomes a solid at the solidus temperature. (D) A solid becomes a liquid at the liquidus temperature.
A
16
Specific atom of an isotope is called
Nuclide
17
Which is more desirable? I. Investing P 2000 at 68 per year compounded interest for three years. II. Investing P2000 per year simple interest for three years.
II
18
Of the following inorganic glasses, which have tetrahedral lattice structures? SiO2, B203, BeF2, GeO2
SiO2, BeF2, and GeO2
19
Which of the following is NOT a structural class of steels?
tool and die
20
If all variables in a linear programming problem are restricted to be integers, which, if any, basic assumption of linear programming is violated?
divisibility
21
How many degrees of freedom does a coin rolling on the ground have?
three
22
Which of the following thermodynamic relations is incorrect?
U = Q -W
23
In preparing a metallographic iron specimen, the grain boundaries are made most visible by which of the following steps?
etching the sample in a 2% solution of nitric acid in alcohol
24
For which of the following is the Program Evaluation and Review Technique (PERT) NOT used?
queueing problems
25
Which of the following best describes the 0.2% offset yield stress?
It is the stress at which the material plastically strains 0.2%.
26
Ductile cast iron and gray cast iron both contain 4% carbon. Ductile cast iron, however, has a higher tensile strength and is considerably more ductile. Which of the following is the major difference that accounts for the superior properties of the ductile iron?
The gray cast iron contains flakes of graphite, whereas the ductile iron contains spheroids of graphite.
27
Which of the following does NOT produce vacancies, interstitial defects, or impurity defects in a material?
slow equilibrium cooling
28
For a rectangular beam under transverse (bending) loading, where is the location of maximum shear stress?
at the neutral axis
29
Which of the following phases of steel has a face-centered cubic structure?
austenite
30
Upon which of the following properties of linear programming is the simplex method based? I. The collection of feasible solutions constitutes a convex set. II. If a feasible solution exists, a basic solution exists where the feasible solutions correspond to the extreme points of the set of feasible solutions. III. Only a finite number of basic feasible solutions exist. IV. If the objective function possesses a finite maximum, at least one opti- mum solution is a basic feasible solution.
I II III and IV
31
Which of the following are true about Fick's first law for diffusion? I. It is only applicable to gases and liquids, not solids. II. The law states that the flux moves from high to low concentration. 111. J, the flux, may be in units of cm°/em"s.
II and III
32
Which of the following statements regarding diffusion in a crystal structure is true?
It often uses an exchange or vacancy mechanism.
33
In Ra 7920, "commission" refers to
PRC
34
Which of the following statements is FALSE?
Hot working causes much strain hardening of the metal.
35
Of the following statements, which is FALSE?
The FORMAT statement may or may not be executed by the program.
36
Which of the following describe(s) the modulus of elasticity of an elastomer? I. It is directly proportional to the number of cross links in the elastomer. II. Its value increases with temperature. III. It is directly proportional to the number of double bonds in the chemical structure.
I and II
37
The usual function of a disconnect switches in high voltage circuits is to
isolate from energized buses, equipment which are not in service
38
Which of the following would have to be added to the main program as a result of the variable XINCH being changed to INCH? Before the change, the function is FUNCTION FOOT(XINCH) FOOT=XINCH 12.0 RETURN END
a REAL variable declaration
39
How tall does a wall mirror have to be in order for you to see all of yourself in the mirror? Imagine you stand a distance "d' from the mirror and your height is "h" and I is the length of mirror required.
L = 1/2 h
40
Low-carbon steels are generally used in the "as rolled" or "as fabricated" state. What is the reason for this?
Their strength generally cannot be increased by heat treatment.
41
Consider a nontrivial linear programming problem in one variable, , with only lower- and upper-bound constraints on 2. At optimum, where will « be in relation to these constraints?
at its upper or lower bound
42
Which of the following correctly describes atoms located at grain boundaries? (A) They are subjected to the same type of interatomic forces that are present in the interior atoms of the crystal. (B) They are located primarily in highly strained and distorted positions (C) They have a higher free energy than atoms in the undisturbed part of the crystal lattice. (D) All of the above are correct.
D
43
Which of the following are true regarding creep? 1. It is caused by the diffusion of vacancies to edge dislocations, permitting dislocation climb. II. It involves the plastic deformation of materials at loads below the vield stress. III. It may involve whole grain sliding.
I, II, and III
44
On an alloy phase diagram, what is the solidus temperature?
The temperature of the solid phase at which the first liquid forms for a given overall composition.
45
What is the most essential attribute of a project manager?
Leadership
46
Under which type of loading does fatigue occur?
repeated load
47
Which of the following statements is FALSE?
Low-alloy steels are a minor group and are rarely used.
48
A 0.15 mdimeter pipe discharges into a 0.10-m diameter pipe. Determine the velocity head (meter/g) in the 0.10-m diameter pipe if the pipes are carrying 0.12 m*3/s of kerosene.
10.93
49
Which of the following would most likely require a steel containing 0.6% carbon that has been spheroidized, cold-drawn, and slightly tempered?
a cutting tool
50
Which of the following is true regarding the ductile-to-brittle transition temper-ature? I. It is important for structures used in cold environments. II. It is the point at which the size of the shear lip or tearing rim goes to zero. III. It is the temperature at which 20 J of energy causes failure in a Charpy -notch specimen of standard dimensions.
I and III
51
IEBE 1284 is a standard communication that defines
parallel communication
52
Which of the following is the correct representation of a eutectic cooling reaction? (The subscripts denote different compositions.)
(liquid) ---> (solid)2 + (solid)2
53
To which of the following can the large discrepancy between the actual and theoretical strengths of metals mainly be attributed?
dislocations
54
Which of the following statements is FALSE?
The acceleration of any point within a homogenous body rotating with a constant angular velocity is proportional to the distance of that point to the center of mass.
55
Which of the following is NOT a good application of network analysis?
inventory theory