Question

Describe a thermo flask​

Answer 1

Explanation:

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.

Answer 2

Answer:

Thermos flasks keep hot liquids hot and cold liquids cold for long hours. It consists of a glass vessel with double walls. The glass vessel is enclosed by a metal or plastic cover for protection against damage. The space between the walls is vacuum which reduces the heat loss due to conduction and convection. The outer surface of the inner wall and the inner surface of the outer wall are silvered (shining). The shining surfaces reduce heat loss due to radiation. An insulating stopper (cork) is used to close the mouth of the vessel. The vessel is kept over an insulating (cork ) pad. It is therefore thermally insulated. Hence, heat does not leave or enter easily and hot liquids remain hot while cold liquids remain cold inside the flask.