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

Options

  1. AThe walls of flask are separated by vacuum and made of glass which is a poor conductor of heat
  2. BThe glass walls themselves have shiny surfaces
  3. CThe surface of inner wall radiates good amount of heat and the surface of outer wall absorbs some of the heat
  4. DThe cork supports are poor conductors of heat

Correct answer

C. The surface of inner wall radiates good amount of heat and the surface of outer wall absorbs some of the heat

Step-by-step solution

(c) The walls of thermos flask are separated by vacuum and made of glass which is poor conductor of heat. The glass walls themselves have shiny surfaces. The radiation emitted by inner wall and that absorbed by outer wall, both are negligible. The cork supports are poor conductors of heat.

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