Asked in NUMS 2023 2023Moderate

If 42J heat is transferred to the system during expansion, what is the change in internal energy when work done is 32J?

Correct answer: B. 10 J

  • A. 74 J
  • B. 10 J
  • C. 116 J
  • D. 106 J

Explanation

The change in internal energy (ΔU) can be calculated using the first law of thermodynamics: ΔU = Q - W Where: * ΔU is the change in internal energy. * Q is the heat added to the system (42 J in this case). * W is the work done by the system (32 J in this case). So, ΔU = 42 J - 32 J = 10 J. The change in internal energy is 10 Joules. This means that the internal energy of the system increased by 10 J due to the heat added and the work done.

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About First Law of Thermodynamics

The first law states that energy is conserved, so the change in a system's internal energy equals heat supplied plus work done on the system, ΔU = q + w. Questions use sign conventions, expansion and compression work, state functions versus path functions, and the relation between internal energy and enthalpy.

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