MD ELEMENTS 20

1. All of the following groups of plastics are thermoplastic, EXCEPT: A. Polyvinylchloride (PVC) and polyvinyl acetate B. Polyethylene, polypropylene, and polysterene C. Tetrafluoroethylene (Teflon, and other fluorocarbons) D. Phenolics, melamine and epoxy

D. Phenolics, melamine and epoxy

2. Which of the following statements is false? A. Ceramics are inorganic-nonmetallic solids that are processed or used at high temperature. B. Metals are chemical elements that form substances that are opaque, lustrous, and good conductors of heat and electricity. C. Oxides, carbides, and nitrides are considered to be within the class of materials known as glasses. D. Most metals are strong, ductile, and malleable. In general, they are heavier than most other substances.

C. Oxides, carbides, and nitrides are considered to be within the class of materials known as glasses.

3. Which of the following is not a viscoelastic material? A. Plastic B. Rubber C. Metal D. Glass

C. Metal

4. In molecules of the same composition, what are variations of atomic arrangements known as? A. Polymers B. Monomers C. Isomers D. Crystal system

C. Isomers

5. What is the atomic packing factor for a simple cubic crystal? A. 0.48 B. 0.52 C. 0.75 D. 0.58

B. 0.52

6. Which of the following statements is false? A. Both copper and aluminum have a face-centered crystal structures. B. Both magnesium and zinc have a hexagonal close-packed crystal structure. C. Iron can have either a face-centered or a body-centered cubic crystal structure. D. Both lead and cadmium have a hexagonal close-packed crystal structure.

D. Both lead and cadmium have a hexagonal close-packed crystal structure.

7. Which crystal structure possesses the highest number of close-packed planes and close-packed direction? A. Simple cubic B. Face-centered cubic C. Body-centered D. Close-packed hexagonal

B. Face-centered cubic

8. What are most common slip planes for face-centered cubic and body-centered cubic structures, respectively? A. Face-centered: (111), body-centered: (110) B. Face-centered: (100), body-centered: (110) C. Face-centered: (110), body-centered: (111) D. Face-centered: (111), body-centered: (100)

A. Face-centered: (111), body-centered: (110)

9. Entrance losses between tank and pipe or losses through elbows, fittings and valves are generally expressed as functions of: A. Kinetic energy B. Friction factor C. Pipe diameter D. Volume flow rate

A. Kinetic energy

10. With regard to corrosion of metals, passivation is the process that: A. Intensifies deterioration temporarily B. Inhibits further deterioration C. Changes the composition of the metal D. Alter the grain size of the metal

B. Inhibits further deterioration

11. How are lines of constant pressure in a fluid related to the force field? A. They are parallel to the force field. B. They are perpendicular to the force field. C. They are at 45° angles to the force field. D. They are perpendicular only to the force of gravity.

B. They are perpendicular to the force field.

12. What are the units of Reynolds number of pipe flow? A. m/s B. lbm/ft-sec² C. ft²/sec D. none of the above

D. none of the above

13. For fully developed laminar flow of fluids through pipes, the average velocity is what fraction of the maximum velocity in the pipe? A. 1/8 B. 1/2 C. 1/4 D. 3/4

B. 1/2

14. For a system to be in equilibrium, the sum of the external forces acting on the system must be: A. Equal to unity B. A maximum C. Indeterminate D. Zero

D. Zero

15. The mass moment of inertia of a cylinder about its central axis perpendicular to a circular cross section is: A. Directly proportional to its radius B. Independent of its radius C. Directly proportional to its length D. Independent of its length

C. Directly proportional to its length

16. How many independent properties are required to completely fix the equilibrium state of a pure gaseous compound? A. 0 B. 2 C. 1 D. 3

B. 2

17. The moment of inertia of any plane figure can be expressed in units of length to the: A. First power B. Second power C. Third power D. Fourth power

D. Fourth power

18. The vector which represents the sum of a group of force vectors is called the: A. Magnitude B. Resultant C. Sum D. Phase angle

B. Resultant

19. Which of the following is not a vector quantity? A. Velocity B. Speed C. Acceleration D. Displacement

B. Speed

20. The stress in an elastic material is: A. Inversely proportional to the material's yield strength B. Inversely proportional to the force acting C. Proportional to the displacement of the material acted upon by the force D. Inversely proportional to the strain

C. Proportional to the displacement of the material acted upon by the force

21. The “SLENDERNESS RATIO” of a column is generally defined as the ratio of its: A. Length to its minimum width B. Unsupported length to its maximum radius of gyration C. Length to its moment of inertia D. Unsupported length to its least radius of gyration

D. Unsupported length to its least radius of gyration

22. The relationship between the extension of a spring and the force required to produce the extension is: A. F= ma B. F= μN C. F= mv²/ R D. F= kx

D. F= kx

23. The linear portion of the stress-strain diagram of steel is known as the: A. Modulus of elongation B. Plastic range C. Irreversible range D. Elastic range

D. Elastic range

24. Principal stresses occur on those planes: A. Where the shearing stress is zero B. Which are 45 degrees apart C. Where the shearing is a maximum D. Which are subjected only to tension

A. Where the shearing stress is zero

25. The ratio of the moment inertia of the cross section of a beam to the section modulus is: A. Equal to the radius of gyration B. Equal to the area of the cross section C. A measure of distance D. Multiplied by the bending moment to determine the stress

C. A measure of distance

26. When an air entertainment agent is introduced into a concrete mix: A. The strength will increase B. The strength will decrease C. The strength will not be affected D. The water/ cement ratio must be reduced from 10-15%

B. The strength will decrease

27. Structural steel elements subjected to torsion develop: A. Tensile stress B. Compressive stress C. Shearing stress D. Bending stress

C. Shearing stress

28. The deflection of a beam is: A. Directly proportional to the modulus of elasticity and moment of inertia B. Inversely proportional to the modulus of elasticity and length of the beam cubed] C. Inversely proportional to the modulus of elasticity and moment of inertia D. Inversely proportional to the weight and length

C. Inversely proportional to the modulus of elasticity and moment of inertia

29. The differential of the shear equation is which one of the following: A. Load on the beam B. Tensile strength of beam C. Bending moment of the beam D. Slope of the elastic curve

A. Load on the beam

30. A vertically loaded beam, fixed at one end and simply supported at the other is indeterminate to what degree? A. First B. Second C. Third D. Fourth

A. First

31. A thin walled pressurized vessel consists of a right circular cylinder with flat ends. Midway between the ends, the stress is greatest in what direction? A. Longitudinal B. Circumferential C. Radial D. At an angle 45° to the longitudinal and circumferential direction

B. Circumferential

32. The bending moment at a section of a beam is derived from the: A. Sum of the moments of all external forces on one side of the section B. Difference between the moments on the side of the section and the opposite side C. Sum of the moments of all external forces on both sides of the section D. Sum of the moments of all external forces between supports

A. Sum of the moments of all external forces on one side of the section

33. The stress concentration factor: A. Is a ratio of the average stress on a section to the allowable stress B. Cannot be evaluated for brittle materials C. Is the ratio of areas involved in an sudden change of cross section D. Is the ratio of the maximum stress produced in a cross section to the average stress over the section

D. Is the ratio of the maximum stress produced in a cross section to the average stress over the section

34. Poisson's Ratio is the ratio of the: A. Unit lateral deformation to the unit longitudinal deformation B. Unit stress to unit strain C. Shear strain to compressive strain D. Elastic limit to proportional limit

A. Unit lateral deformation to the unit longitudinal deformation

35. Hooke's Law for an isotropic homogeneous medium experiencing on-dimensional stress is: A. Stress= E (strain) B. (Force)(area)= (change in length)/ (length) C. Strain= E (stress) D. Force/Area= length/ change in length

A. Stress= E (strain)

36. The modulus of rigidity of a steel member is: A. A function of the length and depth B. Defined as the unit shear stress divided by the unit shear deformation C. Equal to the modulus of elasticity divided by one plus Poisson's ratio D. Defined as the length divided by the moment of inertia

B. Defined as the unit shear stress divided by the unit shear deformation

37. 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: A. Increase at twice the rate, the area of the metal increases B. Increase at the same rate as the area of the metal increases C. Decrease at twice the rate as the area of the metal increases D. Decrease at the same rate as the area of the metal increases

B. Increase at the same rate as the area of the metal increases

38. The linear portion of the stress- strain diagram of steel is known as the: A. Modulus of elasticity B. Irreversible range C. Plastic range D. Elastic range

D. Elastic range

39. In a long column (slenderness ratio>160 which of the following has the greatest influence on its tendency to buckle under a compressive load. A. The modulus of elasticity of the material B. The compressive strength of the material C. The radius of gyration of the column D. The length of the column

D. The length of the column

40. The area of the shear diagram of a beam between any two points on the beam is equal to the: A. Change in shear between the two points B. Total shear beyond the two points C. Average moment between the two point D. Change in moment between the two points

D. Change in moment between the two points

41. Poisson’s ratio is principally used in:
    A. The determination of the capability of a material for being shaped B. The determination of capacity of a material C. Stress- strain relationships where stresses are applied in more than one direction D. The determination of the modulus of toughness

C. Stress- strain relationships where stresses are applied in more than one direction

41. Poisson's ratio is principally used in: A. The determination of the capability of a material for being shaped B. The determination of capacity of a material C. Stress- strain relationships where stresses are applied in more than one direction D. The determination of the modulus of toughness

C. Stress- strain relationships where stresses are applied in more than one direction

42. Young’s modulus of elasticity for a material can be calculated indirectly from which of the following properties of the material? A. Temperature coefficient of expansion and dielectric constant B. Temperature coefficient of expansion and specific heat C. Density and velocity of sound in the material D. Density and inter- atomic spacing in the material

C. Density and velocity of sound in the material

43. . Which of the following is the definition of Joule? A. A unit of power B. A kg m/s² C. A Newton meter D. A rate of change of energy

C. A Newton meter

44. Which of the following metals has the highest specific heat capacity at 100°C? A. Aluminum B. Copper C. Bismuth D. Iron

A. Aluminum

45. Which of the following is a member of the halogen family? A. Sodium B. Hydrogen chloride C. Fluorine D. Phosphorus

C. Fluorine

46. Which of the following metals is the best heat conductor? A. Aluminum B. Gold C. Copper D. Silver

D. Silver

47. When exposed to the atmosphere, which of the following liquids is coldest? A. Oxygen B. Nitrogen C. Argon D. Helium

D. Helium

48. Power may be expressed in units of: A. ft-lbs B. HP- hours C. BTU/hr D. kw-hours

C. BTU/hr

49. Which of the following is not a unit of work? A. N.m B. kg.m²/s² C. erg D. dyne

D. dyne

50. Which of the following statement about entropy is FALSE? A. Entropy of a mixture is greater than that of its components under the same conditions. B. An irreversible process increases entropy of the universe. C. Entropy has the units of heat capacity. D. Entropy of a crystal at 0°F is zero.

D. Entropy of a crystal at 0°F is zero.

51. Work or energy can be a function of all of the following EXCEPT: A. Force and distance B. Power and time C. Torque and angular rotation D. Force and time

D. Force and time

52. What is the combination of one or more metals with a nonmetallic element? A. Metalloid B. Matrix composite C. Inert D. Ceramic

D. Ceramic

53. What do you call an atom that has lost or gain an electron? A. Ion B. Cation C. Hole D. Neutron

A. Ion

54. Polymer comes from Greek words “poly” which means “many” and “meros” which means __________. A. Metal B. Material C. Part D. Plastic

C. Part

55. The engineering materials known as “plastics” are more correctly called __________. A. Polyvinyl chloride B. Polymers C. Polyethylene D. Mers

B. Polymers

56. What is a combination of two or more materials that has properties that the components materials do not have by themselves? A. Compound B. Composite C. Mixture D. Matrix

B. Composite

57. What is a reference sheet for the elements that can be used to form engineering materials? A. Periodic table B. Truth table C. Building blocks of Materials D. Structure of Materials

A. Periodic table

58. Who has been accepted as the author of the periodic table which was developed by chemists in the mid-nineteenth century? A. Vickers B. Knoop C. Rockwell D. Mendeleev

D. Mendeleev

59. What physical property of a material that refers to the point at which a material liquefies on heating or solidifies on cooling? A. Melting point B. Curie point C. Refractive index D. Specific heat

A. Melting point

60. What physical property of a material that refers to the temperature at which ferromagnetic materials can no longer be magnetized by outside forces? A. Melting point B. Thermal conductivity C. Thermal expansion D. Curie point

D. Curie point

61. What is the ratio of the velocity of light in a vacuum to its velocity in another material? A. Refractive index B. Poisson ratio C. Density D. Mach number

A. Refractive index

62. What physical property of a material refers to the amount of weight gain (%) experienced in a polymer after immersion in water for a specified length of time under a controlled environment? A. Dielectric strength B. Electric resistivity C. Water absorption D. Thermal conductivity

C. Water absorption

63. What physical property of a material that refers to the rate of heat flow per unit time in a homogeneous material under steady-state conditions, per unit area, per unit temperature gradient in a direction perpendicular to area? A. Thermal expansion B. Thermal conductivity C. Heat distortion D. Water absorption

B. Thermal conductivity

64. What is the absolute value of the ratio of the transverse strain to the corresponding axial strain in a body subjected to an axial stress? A. Poisson's ratio B. Euler's ratio C. Refractive index D. Dielectric index

A. Poisson's ratio

65. What physical property of a material refers to the highest potential difference (voltage) that an insulating material of given thickness can withstand for a specified time without occurrence of electrical breakdown through its bulk? A. Thermal expansion B. Conductivity C. Dielectric strength D. Electrical resistivity

C. Dielectric strength

66. What physical property of a material refers to the ratio of the amount of heat required to raise the temperature of a unit mass of a substance 1 degree to the heat required to raise the same mass of water to 1 degree? A. Specific heat B. Latent heat C. Heat of fusion D. Heat of fission

A. Specific heat

67. What physical property of a material refers to the temperature at which a polymer under a specified load shows a specified amount of deflection? A. Curie temperature B. Specific heat C. Heat distortion temperature D. Thermal conductivity

C. Heat distortion temperature

68. What mechanical property of a material refers to the nominal stress at fracture in a tension test at constant load and constant temperature? A. Creep strength B. Stress rapture strength C. Compressive yield strength D. Hardness

B. Stress rapture strength

69. What mechanical property of a material refers to the resistance to plastic deformation? A. Rigidity B. Plasticity C. Ductility D. Hardness

D. Hardness

70. What typical penetrator is used in Brinell hardness test? A. 10mm ball B. 120° diamond (brale) C. 1.6 mm diameter ball D. 20° needle

A. 10mm ball

71. What parameter is defined as the temperature at which the toughness of the material drops below some predetermined value, usually 15 ft-lb? A. Nil ductility temperature B. Curie temperature C. Thermal conductivity D. Heat distortion temperature

A. Nil ductility temperature

72. What is obtained by repeatedly loading a specimen at given stress levels until it fails? A. Elastic limit B. Endurance limit or fatigue strength of material C. Creep D. All of the choices

B. Endurance limit or fatigue strength of material

73. What dimensional property of a material refers to the deviation from edge straightness? A. Lay B. Out of flat C. Camber D. Waviness

C. Camber

74. What dimensional property of a material refers to a wavelike variation from a perfect surface, generally much wider in spacing and higher in amplitude than surface roughness? A. Lay B. Waviness C. Surface finish D. Out of flat

B. Waviness

75. Wood is composed of chains of cellulose molecules bonded together by another natural polymer called __________. A. Plastic B. Lignin C. Mer D. Additive

B. Lignin

76. What is a polymer production process that involves forming a polymer chain containing two different monomers? A. Copolymerization B. Blending C. Alloying D. Cross-linking

A. Copolymerization

77. What is the generic name of a class of polymer which is commercially known as "nylon"? A. Polyacetals B. Polyamide C. Cellulose D. Polyester

B. Polyamide

78. By definition, a rubber is a substance that has at least __________ elongation in tensile test and is capable of returning rapidly and forcibly to its original dimensions when load is removed. A. 100% B. 150% C. 200% D. 250%

C. 200%

79. What is a method of forming polymer sheets or films into three-dimensional shapes, in which the sheet is clamped on the edge, heated until it softens and sags, drawn in contact with the mold by vacuum, and cooled while still in contact with the mold? A. Calendering B. Blow molding C. Thermoforming D. Solid phase forming

C. Thermoforming

80. What is a process of forming continuous shapes by forcing a molten polymer through a metal die? A. Calendering B. Thermoforming C. Lithography D. Extrusion

D. Extrusion

81. What chemical property of a material which refers to its ability to resist deterioration by chemical or electrochemical reactions with environment? A. Stereo specificity B. Corrosion resistance C. Conductivity D. Electrical resistance

B. Corrosion resistance

82. What refers to the tendency for polymers and molecular materials to form with an ordered, spatial, three- dimensional arrangement of monomer molecules? A. Stereo specificity B. Conductivity C. Retentivity D. Spatial configuration

A. Stereo specificity

83. What is the ratio of the maximum load in a tension test to the original cross- sectional area of the test bar? A. Tensile strength B. Yield strength C. Shear strength D. Flexural strength

A. Tensile strength

84. What is the ratio of stress to strain in a material loaded within its elastic range? A. Poisson's ratio B. Refractive index C. Modulus of elasticity D. Percent elongation

C. Modulus of elasticity

85. What is a measure of rigidity? A. Stiffness B. Hardness C. Strength D. Modulus of elasticity

D. Modulus of elasticity

86. The greatest stress which a material is capable of withstanding without a deviation from acceptable of stress to strain is called __________. A. Elongation B. Proportional limit C. Yield point D. Elastic limit

B. Proportional limit

87. What refers to the stress at which a material exhibits a specified deviation from proportionality of stress and strain? A. Tensile strength B. Shear strength C. Yield strength D. Flexural strength

C. Yield strength

88. What is the amount of energy required to fracture a given volume of material? A. Impact strength B. Endurance limit C. Creep strength D. Stress rupture strength

A. Impact strength

89. What mechanical property of material which is a time-dependent permanent strain under stress? A. Elongation B. Elasticity C. Creep D. Rupture

C. Creep

90. In tensile testing, the increase in the gage length measured after the specimen fractures within the gage length is called __________. A. Percent elongation B. Creep C. Elasticity D. Elongation

A. Percent elongation

91. What is the resistance of a material to plastic deformation? A. Hardness B. Stiffness C. Creepage D. Rigidity

A. Hardness

92. What is the maximum stress below which a material can theoretically endure an infinite number of stress cycles? A. Endurance state B. Endurance test C. Endurance limit D. Endurance strength

C. Endurance limit

93. What is a substance that attracts piece of iron? A. Conductor B. Semiconductor C. Magnet D. All of the choices

C. Magnet

94. Which of the following is a natural magnet? A. Steel B. Magnesia C. Lodestone D. Soft iron

C. Lodestone

95. Which of the following materials has permeability slightly less than that of free space? A. Paramagnetic materials B. Non-magnetic materials C. Ferromagnetic materials D. Diamagnetic materials

D. Diamagnetic materials

96. What materials has permeabilities slighter greater than that of free space? A. Paramagnetic materials B. Non-magnetic materials C. Ferromagnetic materials D. Diamagnetic materials

A. Paramagnetic materials

97. Which of the following materials have very high permeabilities? A. Paramagnetic materials B. Non-magnetic materials C. Ferromagnetic materials D. Diamagnetic materials

C. Ferromagnetic materials

98. What is defined by ASTM as a material that contains as an essential ingredient an organic substance of large molecular weight, is solid in its finished state, and at some stage in its manufactured or in its processing into finished articles, can be shaped by flow? A. Metal B. Metalloid C. Plastic D. Ceramic

C. Plastic

99. Some polymetric materials such as epoxies are formed by strong primary chemical bonds called __________. A. Metallic bond B. Vander Waals bond C. Cross linking D. Covalent bond

C. Cross linking