The polymer having an amide linkage is

Which of the following polymers is used to obtain tyre cords?

Natural rubber has

Which of the following is used in the vulcanization of rubber?

If $\bar{M}_w$ is the weight average molecular weight and $\bar{M}_n$ is the number average molecular weight of a polymer, the poly dispersity index $(PDI)$ of the polymer is given by

Match the polymers in column $- A$ with their main uses in column $- B$ and choose the correct answer.

Column $- A$	Column $- B$
$(A)$ Polystyrene	$(i)$ Paints and lacquers
$(B)$ Glyptal	$(ii)$ Rain coats
$(C)$ Polyvinyl chloride	$(iii)$ Manufacture of toys
$(D)$ Bakelite	$(iv)$ Computer discs