Tuesday, January 25, 2011

Synthetic fibres and plastics


Q1. Fill in the blanks:
a)     Synthetic fibres are also called _______________ or ______________ fibres.
b)    Terycot is a mixture of _________________ and _______________.
c)     ___________ is used for making bottles of soft drinks, oils etc.
d)    ______________ was the first man-made plastic.
e)     Thermosetting plastics have a __________________ arrangement of molecules.
f)      Teflon is a ________________ plastic.
g)     _______________ is a flame resistant plastic.

Q2. Match the following:
1.     Terylene                          a) Prepared by using wood
2.     Teflon                              b) Used for making
                                                  parachutes and stockings
3.     PET                                 c)  Fabrics do not wrinkle
4.     Rayon                              d) Used to make non-stick
5.     Nylon                              e)  Used for making magnetic

Q3. Synthetic fibres are not considered environment friendly. Why?

Q4. What do you understand by high tensile strength?

Q5. Define polymerization.

Q6. Why synthetic fibres are used for making dress materials?

Q7. a) What is the other name of artificial silk?
       b) How is it prepared?
       c) Why is it also called regenerated fibre?

Q8. Explain the difference between:
a)     thermoplastic and thermosetting plastic
b)    biodegradable and non-biodegradable materials

Q9. Write 3 uses of melamine.

Q10. Why is Teflon used to make non-stick cookwares?

Q11. Explain why the following are made of thermosetting plastics:
a)     Saucepan handles
b)    Electric plugs/ switches/ plug boards

Q12. Why is melamine coated on uniform of fireman?

Q13. Why electrical wires have plastic covering?  OR 
         Why handles of screw drivers are made of plastic?

Q14. Explain why plastic containers are favoured for storing food?

Q15. Write any 2 measures that can be taken to control the damage caused by plastic waste.