Monomer units of $Dacron$ polymer are :

Nylon-$6,6$ is a condensation polymer of two monomers $X$ and $Y$. The number of $-CH_2-$ groups in $X$ and $Y$ are respectively

$A$ polymer sample contains $10$ molecules each with molecular mass $5,000$ and $5$ molecules each with molecular mass $50,000$. The number average molecular mass of the polymer sample is

Nylon yarns are usually

Terylene is a

Identify the use of $LDP$ from the following.