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MHT CET Medical202624 April 2026Morning ShiftChemistryThermodynamics (C)Actual

Which of the following is applicable for isothermal process?

Options

  1. AW=-Q
  2. B- U=-W
  3. CU=Q_v
  4. DQ_p= U+P_ ext V

Correct answer

A. W=-Q

Step-by-step solution

For an isothermal process, the temperature of the system remains constant, which means T = 0 . For an ideal gas, the change in internal energy is given by U = nC_v T . Since T = 0 , the change in internal energy is zero, so U = 0 . According to the first law of thermodynamics: U = Q + W Substituting U = 0 into the equation, we get: 0 = Q + W W = -Q This indicates that the work done on the system is equal to the negative of the heat absorbed by the system. Answer: W=-Q

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