Sample interview questions: Can you explain the basic principles of thermodynamics?
Sample answer:
- First Law of Thermodynamics (Conservation of Energy):
- Energy can neither be created nor destroyed, only transferred or transformed from one form to another.
- Heat and work are two ways energy can be transferred.
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The change in internal energy (∆U) of a system is equal to the heat (Q) added to the system minus the work (W) done by the system.
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Second Law of Thermodynamics (Entropy):
- The total entropy of an isolated system always increases over time.
- Entropy is a measure of disorder or randomness in a system.
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The second law implies the directionality of time, explaining why certain processes, like heat flowing from hot to cold, occur naturally while the reverse does not.
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Third Law of Thermodynamics:
- The entropy of a perfect crystal at absolute zero is zero.
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This law implies that at absolute zero, all physical systems reach a state of minimum energy and maximum order.
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Thermodynamic Systems:
- Closed system: No mass transfer occurs between the system and its surroundings.
- Open system: Mass transfer occurs between the system and its surroundings.
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Isolated system: No mass or energy transfer occurs between the system and its surroundings.
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Thermodynamic Processes:
- Isothermal process: Temperature remains constant.
- Adiabatic process: No heat transfer occurs.
- Isochoric process: Volume remains constant.
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Isobaric process: Pressure remains const… Read full answer