Question

why are the inner walls of a thermos flask polished?​

Answer 1

Answer:

The wall of thermoflask are polished because shiny surface are good radiators of heat. Since we intend to keep in the vacuum flask and not have it radiated, Outside the shiny surface is best option. A black wall is bad option as they are good emitter and absorber of heat radiation.

Answer 2

Answer : The wall of thermos flask polished because shiny surface are good radiators of heat .

Hope it helps ...