Question

 i will mark the brainlist for the first answer.Draw a neat labelled diagram of a thermos flask. How does it prevent transfer of heat by conduction, convection or radiation?

Answer 1

When a hot substance is placed in a thermos flask, the heat going out gets reflected due to the shining surface of the inner tube. Hence,heat is radiated. Neither conduction nor convection of the heat occurs because of the vacuum. As a result,heat is not transferred to the outer cooler region and is retained inside for a long time. Still, a little heat is lost from around the lid and by a small amount of conduction through the glass. Therefore, the hot substance does not remain as hot after two and three hours.

HOPE IT HELPS:-)

Answer 2

Answer:

Hope you understand the diagram