© Mikell P. Groover 2012
Chapter 9 COMPOSITE MATERIALS
Multiple Choice Quiz
There are 23 correct answers in this multiple choice quiz (some questions have multiple answers
that are correct). To achieve a perfect score on the quiz, all correct answers must be given. Each
correct answer is worth 1 point. Each omitted answer or wrong answer reduces the score by 1
point. Percentage score on the quiz is based on the total number of correct answers.
9.1
A composite material is a material system composed of two or more physically distinct
phases whose combination produces aggregate properties that are different from those of
its constituents: (a) true or (b) false?
9.2
Anisotropic means which one of the following: (a) composite materials with compositions
consisting of more than two materials, (b) properties are the same in every direction, (c)
properties vary depending on the direction in which they are measured, or (d) strength and
other properties are a function of curing temperature?
9.3
The reinforcing phase is the matrix within which the secondary phase is imbedded: (a) true
or (b) false?
9.4
Which one of the following reinforcing geometries offers the greatest potential for
improving strength and stiffness in the resulting composite material: (a) continuous fibers,
(b) discontinuous fibers, (c) flakes, (d) particles, or (e) infiltrated phase?
9.5
Wood is which one of the following composite types: (a) ceramic matrix composite, (b)
metal matrix composite, or (c) polymer matrix composite?
9.6
Which of the following materials are used as fibers in fiber-reinforced plastics (four best
answers): (a) aluminum oxide, (b) boron, (c) cast iron, (d) E-glass, (e) epoxy, (f) Kevlar 49,
(g) polyester, and (h) silicon?
9.7
In some composite materials, a third ingredient is added to promote bonding of the primary
and secondary phases. This third ingredient is called which one of the following: (a)
adhesive, (b) binder, (c) interface, (d) interphase, or (e) joiner?
9.8
The rule of mixtures is used for which of the following purposes related to composite
materials (one best answer): (a) calculating the proportions of each material to include in the
composite material, (b) calculating the strength of a fiber-reinforced composite material, or
(c) calculating the weighted average of the primary and secondary material properties?
9.9
Which of the following metals are widely used as the matrix metals in tungsten carbide and
titanium carbide cermets (two best answers): (a) aluminum, (b) chromium, (c) cobalt, (d)
lead, (e) nickel, and (f) vanadium?
9.10 Which of the following metals are used as the matrix material in fiber-reinforced metal
matrix composites (two best answers): (a) aluminum, (b) copper, (c) iron, (d) magnesium,
and (e) zinc?
9.11 Ceramic matrix composites are designed to overcome which of the following weaknesses of
ceramics (two best answers): (a) compressive strength, (b) hardness, (c) hot hardness, (d)
modulus of elasticity, (e) tensile strength, and (f) toughness?
Excerpts from this work may be reproduced by instructors for distribution on a not-for-profit basis for testing or instructional purposes only to
students enrolled in courses for which the textbook has been adopted. Any other reproduction or translation of this work beyond that permitted
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© Mikell P. Groover 2012
9.12 Most plastic molding compounds include fillers and therefore can be classified as polymer
matrix composites: (a) true or (b) false?
9.13 Which one of the following polymer types are most commonly used in polymer matrix
composites: (a) elastomers, (b) thermoplastics, or (c) thermosets?
9.14 Which of the following materials are not composites (two correct answers): (a) cemented
carbide, (b) phenolic molding compound, (c) plywood, (d) portland cement, (e) rubber in
automobile tires, (f) wood, and (g) 1020 steel?
9.15 In the Boeing 787 Dreamliner, what percentage of the aircraft consists of composite
materials (two correct answers): (a) 12% by volume, (b) 20% by volume, (c) 50% by
volume, (d) 80% by volume, (e) 12% by weight, (f) 20% by weight, (g) 50% by weight, and
(h) 80% by weight?
Excerpts from this work may be reproduced by instructors for distribution on a not-for-profit basis for testing or instructional purposes only to
students enrolled in courses for which the textbook has been adopted. Any other reproduction or translation of this work beyond that permitted
by Sections 107 or 108 of the 1976 United States Copyright Act without the permission of the copyright owner is unlawful.