Question

On burning silk it gives out the smell of burning hair why

Answer 1

Silk is made out of silk worms. They create hair like fibers which are woven to form silk fabric. That's why they give hair burning smell.

Answer 2

It is because silkbis prod. From silk worms they are heated in water and spun into yarn . Therefore it makes up hair like structure and therefore looks like hair and have the same property and therefore smells like hair.