Which one of the following statements regarding a thermos flask is NOT correct?

A thermos flask is designed to minimize heat transfer via conduction, convection, and radiation. The walls are made of glass, which is a poor conductor of heat. The space between the double walls is a vacuum, which prevents heat loss by conduction and convection. The glass walls are silvered (shiny) to reflect thermal radiation. Statement 3 is incorrect because the silvered surfaces are intended to reflect radiation back to the source rather than having the outer wall absorb it. Specifically, the silvering on the outer surface of the inner wall reflects heat back into the liquid, while the silvering on the inner surface of the outer wall reflects external heat away. Cork or plastic supports and stoppers are used because they are poor conductors, further reducing heat loss.

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 7: Heat Transfer in Nature > 7.1 Conduction of Heat > p. 91