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JEE Main 2023 (24 Jan, Shift 1) · Heat, Work & First Law of Thermodynamics

Heat, Work & First Law of Thermodynamics question from JEE Main 2023 (24 Jan, Shift 1)

Q13JEE Main 2023 · 24 JAN · SHIFT 1Medium

Heat, Work & First Law of Thermodynamics

1 g of a liquid is converted to vapour at 3 ×\times 1055 Pa pressure. If 10% of the heat supplied is used for increasing the volume by 1600 cm33 during this phase change, then the increase in internal energy in the process will be:

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Answer: (b)

  1. Work done in expansion: W=PΔV=3×105×1600×10−6=480 JW = P\Delta V = 3\times10^{5} \times 1600\times10^{-6} = 480\text{ J}
  2. This is 10% of heat supplied: Q=4800 JQ = 4800\text{ J}
  3. ΔU=Q−W=4800−480=4320 J\Delta U = Q - W = 4800 - 480 = 4320\text{ J}
  4. So the answer is (b) 4320 J.
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