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Composite materials Viva Question and Answers

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Q1- What is a composite?
a. Recycled waste
b. A chemical reaction
c. The latest computer software
d. A structural material consisting of two or more constituents. 

Answer:
A composite is a structural material which consists of combining two or more constituents

Q2- Advanced composites are
a. naturally found
b. traditionally used in aerospace industries
c. low performance composites
Answer:
Advanced composites are traditionally used in aerospace industries 

Q3- Composites are easy to repair
a. True
b. False
Answer: 
Composites are generally difficult to repair 

Q4- What fiber factors contribute to the mechanical performance of a composite?
a. Length
b. Orientation
c. Shape
d. All of the above
Answer: 
Length, orientation, and shape all contribute to the mechanical performance of a composite 

Q5- PMC stands for:
a. Polymer Metal Composition
b. Polymer Matrix Composite
c. Polyethylene Metal Composition
Answer: 
PMC stands for Polymer Matrix Composite 

Q6-The most common advanced composites are
a. Metal Matrix Composites
b. Polymer Matrix Composites
c. Ceramic Matrix Composites
Answer: 
The most common advanced composites are Polymer Matrix Composites

Q7- The most common fibers used in advanced polymer composites are
a. glass, steel, and aluminum
b. glass, graphite, and kelvar
c. glass, steel, and kelvar
Answer: 
The most common fibers used in advanced polymer composites are glass, graphite, and kelvar

Q8- E-glass type fiber is used for
a. Electrical applications
b. Environmental applications
c. Evaporative applications
Answer: 
E-glass type fiber is used for electrical applications

Q9- One of the major drawbacks of composites is
a. high cost of fabrication
b. no body needs them
c. they are extremely heavy
Answer: 
One of the major drawbacks of composites is their relatively high cost of fabrication

Q10- SMC stands for
a. Structural Metal Composite
b. Strong Metal Composite
c. Sheet Molding Compound
Answer: 
SMC stands for Sheet Molding Compound

Q11- Annual growth of composites is at a steady rate of
a. 5 percent
b. 10 percent
c. 15 percent
d. -15 percent
Answer: 
Annual growth of composites is at a steady rate of 10 percent

Q12- Reducing one pound of mass in a commercial aircraft can save up to how many gallons per year?
a. 50
b. 350
c. 3500
d. 30000
Answer: 
Reducing one pound of mass in a commercial aircraft can save up to 350 gallons per year?

Q13- The material of the fiber directly influences the mechanical performance of a composite
a. True
b. False
Answer: 
The material of the fiber directly influences the mechanical performance of a composite

Q14- The most common fiber shape is
a. Rectangular
b. Triangular
c. Circular
Answer: 
The most common fiber shape is circular

Q15- The units of fracture toughness are
a. MPa-m
b. MPa^0.5-m
c. MPa-m^0.53
Answer: 
The units of fracture toughness are MPa-m^0.5

Q16- A typical range of carbon content in carbon fiber is
a. 93-95%
b. 92-95%
c. 93-94%
d. 90-95%

Answer: 
A typical range of carbon content in carbon fiber is 93-95%

Q17- Graphite fibers have one of the following carbon content
a. 99%
b. less than 99%
c. more than 99%
d. 98%3
Answer: 
Graphite fibers have more than 99% carbon content

Q18- Thermoset plastic polymers have the following type of bonding
a. Covalent bond
b. Vanderwaals bond
c. Atomic bond
d. none of the above

Answer: 
Thermoset plastic polymers have Vanderwaals type bonding

Q19- Current service temperature limits for polymers reach
a. 750 degrees Fahrenheit
b. 1750 degrees Fahrenheit
c. 450 degrees Fahrenheit
d. 350 degrees Fahrenheit

Answer: 
Current service temperature limits for polymers reach 750 degrees Fahrenheit 

Q20- Mechanical fasteners are made of what type of composite
a. Boron-Epoxy
b. Graphite-Epoxy
c. Carbon-Carbon
d. All of the above
Answer: 
Mechanical fasteners are made of Carbon-Carbon composites

Q21- Isotropic means
a. a material with different properties in all directions
b. a material with the same properties in all directions
c. a material with elastic properties
d. none of the above
Answer: 
Isotropic means a material with the same properties in all directions

Q22- Composite materials are
a. isotropic but not homogeneous
b. homogeneous but not isotropic
c. both homogeneous and isotropic
d. neither homogeneous or isotropic
Answer: 
Composite materials are neither homogeneous or isotropic

Q23- Anisotropic materials are
a. materials with different properties in all directions
b. materials with the same properties in all directions
c. materials with the same properties in two perpendicular directions
d. none of the above
Answer: 
Anisotropic materials have different properties in all directions

Q24- Inter-ply hybrid composites consist of
a. two or more different composite systems
b. two or more different fibers used in the same ply
c. both a and b
d. none of the above
Answer: 
Inter-ply hybrid composites consist of two or more different composite systems

Q25- Aramid fibers are made up of
a. Carbon, Hydrogen, Oxygen and Graphite
b. Carbon, Hydrogen, Oxygen and Nitrogen
c. Carbon, Hydrogen, Oxygen
d. Carbon, Hydrogen, Nitrogen
Answer: 
Aramid fibers are made up of Carbon, Hydrogen, Oxygen and Nitrogen

Q26- A typical example of thermoplastics include
a. polyethylene
b. polyesters
c. phenolics
Answer: 
A typical example of thermoplastics include polyethylene

Q27- Polymer matrix composites are manufactured in the automotive industry where short production runs are necessary by
a. filament winding
b. autoclave forming
c. resin transfer molding
d. none of the above
Answer: 
Polymer matrix composites are manufactured in the automotive industry where short production runs are necessary by resin transfer molding

Q28- Which of the following composites are replacing metals in golf club shafts
a. Carbon-Carbon
b. Graphite-Epoxy
c. Boron-Epoxy
d. none of the above
Answer: 
Graphite-Epoxy is replacing metals in golf club shafts

Q29- Which of the following is a drawback for phenolic resin systems
a. high cost
b. low mechanical strength
c. high void content
d. brittleness
Answer: 
High cost is a drawback for phenolic resin systems

Q30- Bullet proof vests use
a. Kelvar
b. Graphite
c. Boron
d. Glass
Answer: 
Bullet proof vests use Kelvar

Q31- High performance applications in the aerospace industry use
a. Graphite
b. Boron
c. Kelvar 49
d. Kelvar 293
Answer: 
High performance applications in the aerospace industry use Kelvar 49

Q32- Thermoset polymers show which of the following
a. Decompose on heating
b. Soften on heating
c. Harden on heating
d. none of the above
Answer: 
Thermoset polymers decompose on heating

Q33- The performance indicator for buckling of a rod under a compressive load is
a. Young's modulus / density
b. (Young's modulus ^ 0.5) / density
c. (Young's modulus ^ 0.3333) / density. 

Answer: 
The performance indicator for buckling of a rod under a compressive load is (Young's modulus ^ 0.5) / density

Q34- Specific modulus is given by
a. Square root of Young's modulus / density
b. Strength / density
c. Young's modulus / density
Answer: 
Specific modulus is given by Young's modulus / density

Q35- Glass fibers are made from
a. slice glass
b. vapor deposition method
c. graphite
Answer: 
Glass fibers are made from slice glass

Q36- Which polymer is not desirable for smoke emmision?
a. Phenolic
b. Epoxy
c. Polyester
d. Polymide
Answer: 
Polymide is not desirable for smoke emmision

Q37- Which polymer has the maximum strength?
a. Phenolic
b. Epoxy
c. Polyester
d. Polymide
Answer: 
Epoxy has the maximum strength

Q38- Which polymer has the highest service temperature?
a. Phenolic
b. Epoxy
c. Polyester
d. Polymide4
Answer: 
Polymide has the highest service temperature




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