Explain how the loss of heat (or transfer of heat) due to modes of transfer of heat is 1. Explain how the las minimised in a thermos flask.

Explanation

Transfer of heat is thermos is minimised as under.
(i) By conduction: As in conduction heat can transfer by contact of material medium. In thermos air is evacuated between the walls so heat transfer in stopped by conduction mode.
(ii) By convection:
As in conduction heat can transfer by contact of material medium. In thermos air is evacuated between the walls so heat transfer in stopped by conduction mode.
(iii) By convection: As convection mode also require material (fluid) medium and there is nothing between the