Question

In a vacuum flask, which methods of heat transfer are prevented by the

vacuum?​

Answer 1

Vacuum in a vacuum flask prevents heat transfer through process of conduction and convection.

Vacuum in a vacuum flask prevents heat transfer through process of conduction and convection.It is so because, in conduction there needs a direct contact for transfer of heat and there is vaccum between two layers, so conduction can't transfer heat in this case. And in convection, heat is transferred by molecular motion in fluid (liquid or gas). But due to vaccum's presence between two layers, molecular motion is not possible So convection is also impossible for this case.

Answer 2

Answer:

The Physics

A thermos flask has double walls, which are evacuated and the vacuum bottle is silvered on the inside. The vacuum between the two walls prevents heat being transferred from the inside to the outside by conduction and convection.