Question

The walls of thermo-flask are polished because

• A. shining bodies are good absorber of heat
• B. shining bodies are good radiator of heat
• C. shining bodies have emisivity as one
• D. none of the above

Answer 1

Answer: (B)

shining bodies are good radiator of heat

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.