Composite Materials Quiz

Answer all the questions below to test your knowledge of composite materials, matrices, reinforcements, fibreglass, steel-reinforced concrete, laminates and their uses. Hit the check answers button to get your score.

Dental fillings are composed of a composite material.

sportswear and equipment are almost all composed of composite materials.

1. What is meant by a composite material?

a) A material made from two or more different materials combined to give improved properties.
b) A pure material made of only one type of atom.
c) A mixture that can be easily separated by filtration.
d) Any metal alloy used in construction.

2. Which statement about the matrix and the reinforcement in a composite is true?

a) The reinforcement holds everything together and the matrix provides most of the strength.
b) The matrix is the continuous phase that holds the reinforcement in place and protects it, while the reinforcement provides most of the strength and stiffness.
c) The matrix and reinforcement are two names for exactly the same thing.
d) The reinforcement is always a liquid and the matrix is always a solid.

3. In steel-reinforced concrete, what acts as the reinforcement?

a) The cement.
b) The sand and gravel (aggregate).
c) The steel rods or mesh (rebar).
d) The water used to mix the concrete.

4. In a composite material, the continuous phase that surrounds and supports the other material is called the . The fibres or particles that provide most of the strength and stiffness are called the .

5. Which of the following is an example of a composite material?

a) Pure aluminium metal.
b) Steel-reinforced concrete.
c) Distilled water.
d) Oxygen gas (O₂).

6. Concrete itself is also a composite material. Which statement best describes its structure?

a) The cement forms a matrix that binds sand and gravel (aggregate) together.
b) Pure water holds dissolved salt crystals.
c) Steel rods are the matrix and concrete is the reinforcement.
d) It contains only one pure substance.

7. Which statement about fibreglass (GRP) is correct?

a) It is made of glass fibres in a polymer resin, where the glass fibres are the reinforcement and the polymer is the matrix.
b) It is just ordinary glass with no other materials added.
c) It is a metal strengthened with carbon fibres.
d) It is a ceramic with trapped air bubbles.

8. What is a laminate?

a) A single, pure slab of metal.
b) A composite made by bonding layers of materials together, such as plywood.
c) A liquid mixture of polymers and dyes.
d) A gas mixture used in balloons.

9. Which property is often a major advantage of composites like carbon-fibre-reinforced polymer (CFRP) used in aircraft and racing bikes?

a) Very high density.
b) A high strength-to-weight ratio (strong but lightweight).
c) They are always excellent electrical conductors.
d) They are always transparent.

10. Which component is correctly matched with a composite material commonly used for it?

a) Car windscreen – fibreglass only.
b) Bridge suspension cables – plain concrete.
c) Boat hulls – fibreglass (glass fibres in a polymer matrix).
d) Artificial teeth – steel-reinforced concrete.

11. Why can different composite materials be designed for different uses?

a) Because they are all pure substances with identical properties.
b) Because the matrix and reinforcement can be changed to give different combinations of properties.
c) Because only metals are used in composites.
d) Because their properties cannot be controlled.