Which is used in motion picture films?

Which of the following polymers is used in the preparation of gaskets?

Which of the following monomers form biodegradable polymers?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ Dacron is an example of polyester polymer.
Reason $R:$ Dacron is made up of ethylene glycol and terephthalic acid monomers.
In the light of the above statements,choose the most appropriate answer from the options given below.

$A$ polymer sample contains $3$ molecules of molar mass $10^3$, $3$ molecules of molar mass $500$, and $4$ molecules of molar mass $200$. What is its weight average molecular mass?

Monomer units of $Dacron$ polymer are :