Enthalpy change in a closed system equals the heat transferred during a reversible process occurring at constant________________?
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Answer: A. pressure
Explanation
Enthalpy is defined as internal energy plus the product of pressure and volume inside the system. During a reversible constant pressure process, the heat transferred accounts for both internal energy and boundary work. The first law of thermodynamics confirms that this total energy transfer equals the exact change in enthalpy. Enthalpy is a state function widely used in thermodynamics to analyze fluid flow and heat exchangers. A closed system restricts mass transfer while permitting energy transfer through heat and boundary work interactions. Reversible processes proceed through a continuous sequence of equilibrium states without any internal dissipative losses.
Option B corresponds to isothermal processes where temperature remains constant instead of the system pressure. Option C relates to internal energy changes rather than enthalpy during constant volume thermodynamic processes. Option D incorrectly treats internal energy as a process condition rather than a fundamental thermodynamic property.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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