For air and most common gases below 500°C, the ratio y = cp/cv can be reliably estimated as_____________________?
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Answer: C. 1.4
Explanation
For diatomic gases like air at moderate temperatures, gamma equals approximately 1.4. The specific heat ratio is fundamental for analyzing compressible gas flows and thermodynamic cycles. Molecular degrees of freedom dictate the constant specific heat values yielding this standard ratio. Specific heats at constant pressure and constant volume vary slightly with temperature changes. Thermodynamic relations for adiabatic processes depend directly upon this specific heat ratio. Air is treated as an ideal diatomic gas for engineering calculations below five hundred degrees Celsius.
Aerospace engineers use the specific heat ratio when calculating supersonic nozzle flow parameters. Internal combustion engine cycle analysis requires accurate gamma values for compression expansion work. Pneumatic system design relies on thermodynamic equations incorporating standard gas property ratios. An option of zero point eight represents an incorrect ratio uncharacteristic of common diatomic gases. A ratio of one would imply zero compressibility effects which contradicts actual gas behavior. Higher values like one point eight apply to monatomic gases with fewer molecular degrees of freedom.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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