CDS 2026 (I) General Knowledge, question 13

Topic: Physics

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Q13

Which one among the following has the least coefficient of thermal conductivity ?

  1. (a) H2H_{2}Correct answer
  2. (b) H2OH_{2}O
  3. (c) CuCu
  4. (d) AlAl

Solution.

Answer: (a) H2H_{2}

  1. At ordinary room conditions, hydrogen gas has a lower thermal conductivity than liquid water, copper or aluminium.
  2. Approximate values are 0.18 for hydrogen and 0.6 for liquid water in W m⁻¹ K⁻¹, while the metals are far higher.