Question

Draw a neat and labeled diagram of a vacuum flask (thermos flask). Explain, how it minimizes loss of heat by preventing conduction, convection, and radiation.

Answer 1

The flask consists of double-walled glass containers with a vacuum between the walls A and B to prevent heat loss due to conduction and convection as a vacuum is the excellent insulator .to prevent heat loss by radiation, the inner side of the wall A and outer side of wall B is silvered. It has a narrow mouth which is closed by a non-conducting rubber stopper.