When a system executes a series of processes and reverts to its initial condition__________________?
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Answer: D. sum of heat and work transfer will be zero
Explanation
Internal energy is a state function, meaning its net change over any complete cycle is zero. According to the first law of thermodynamics, net heat transfer equals net work in a cycle. The algebraic sum of all heat and work transfers across a complete cycle equals zero. Thermodynamic cycles consist of a series of processes returning the working fluid to initial states. State properties depend only on the current condition, not the historical path taken. Cyclic devices like power plants operate by continuously repeating these thermodynamic processes.
Power generation systems rely on closed thermodynamic cycles to continuously produce mechanical work. First law energy balances verify the performance and efficiency of cyclical thermal machinery. Engineers analyze net heat and work exchanges to optimize thermodynamic cycle performance. Option A describes equilibrium conditions but does not explain the net energy transfer sum. Option B describes a closed cycle without stating the crucial net energy transfer balance. Option C ignores the net conservation of energy principle across a complete thermodynamic cycle.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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