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JAMB Physics 1979 Question 50

Question 50

Heat Transfer

Which of the following statements is correct? Silvered walls of a vacuum flask are used to prevent

  1. A.heat loss due to conduction
  2. B.vacuum loss
  3. C.heat entry into the inner flask due to convection
  4. D.heat loss due to radiation
  5. E.heat loss due to convection
Show the answer and explanation

Answer: D (heat loss due to radiation)

Explanation

Shiny silvered surfaces are poor emitters and good reflectors of radiant heat, so they cut down heat transfer by radiation. The vacuum deals with conduction and convection.