10.(a) What are aramids? (b) What are their desirable properties? (c) What are their applications in sports equipment industries?
11. (a) In what class of materials does GaAs (gallium arsenide) belong? (b) What are its desirable properties? (c) What are its applications in electronic industries?
12. Nickel-base superalloys are used in the structure of aircraft turbine engines. What are the major properties of this metal that make it suitable for this application?