Question

how does a thermos flask minimise heat l​

Answer 1

Answer:

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.

Explanation:

The outer surface of its inner wall and the inner surface of its outer wall are silvered. This prevents heat transfer due to radiation. The space between the two walls is almost vacuum and the walls are sealed at the top.

Answer 2

Explanation:

A thermos flask or a vacuum flask is used to keep a hot liquid hot and a cold liquid cold for a long time, by preventing the loss or gain of heat energy due to conduction, convection and radiation.

The double-walled glass vessel and vacuum prevents heat loss by conduction.

Hope it helps...