Under what expansion conditions does a gas deliver the greatest amount of mechanical work___________________?
Show answer Hide answer
Answer: C. Isobarically
Explanation
Isobaric expansion maintains constant maximum pressure throughout the entire volume increase. Work done equals the integral of pressure with respect to volume change in closed systems. Higher average operating pressure during expansion yields greater mechanical work output. Work is represented graphically as the area underneath a process curve on a pressure-volume diagram. Isothermal expansions feature dropping pressures, resulting in smaller work areas than isobaric paths. Adiabatic expansions experience rapid pressure drops due to simultaneous temperature reductions.
Designing efficient pneumatic actuators requires selecting expansion paths that maximize work output. Thermodynamic cycle analysis compares isobaric and isothermal processes for power generation. Engineers optimize engine cylinder expansion strokes to extract the maximum mechanical energy. Option A non-uniform expansion leads to unpredictable and inefficient mechanical work delivery. Option B adiabatically expanded gases experience rapid pressure drops, reducing total work output. Option D isothermally expanded gases suffer from pressure decay as volume increases.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. A liquid maintained at a pressure exceeding its equilibrium vapor pressure at the prevailing temperature is known as a _____________ liquid?
Show answer Hide answer
Answer: A. Sub-cooled
Sub-cooled liquids exist at temperatures lower than the saturation temperature for a given pressure. Alternatively, maintaining a liquid at a pressure exceeding its vapor pressure produces sub-cooling. This prevents boil...
Q2. A long cylinder and a sphere of identical 5 cm diameters are fabricated from the same porous substrate with the cylinder ends sealed. Both objects are saturated with a sodium chloride solution and then immersed for a brief, equal duration in a vigorously stirred water bath. Let Xc and Xs denote the remaining salt fractions in the cylinder and sphere. Which statement holds true?
Show answer Hide answer
Answer: C. Xc < Xs
Geometric surface-to-volume ratio differences affect mass transfer and diffusion rates significantly. Spheres and cylinders exhibit different internal diffusion path lengths for dissolved salt extraction. The cylinder le...
Q3. A polymeric material is classified as an elastomer if its elongation exceeds 100%. Beyond what percentage elongation is it specifically designated as rubber _______________ percent?
Show answer Hide answer
Answer: B. 200
Elastomers undergo large elastic deformations when subjected to tensile mechanical stress. Vulcanization creates cross-linked polymer networks that enable extreme stretching capabilities. Specifically designating an elas...
Q4. What sub-surface masonry structure relies on anaerobic bacterial action to drive biochemical waste decomposition___________________?
Show answer Hide answer
Answer: D. Septic tank
Septic tanks utilize sealed underground masonry structures to promote anaerobic bacterial decomposition. Microorganisms break down complex organic solid waste in the absence of dissolved oxygen. This biochemical process...
Q5. A rigid, perfectly insulated vessel of volume V has a partition dividing it into equal halves. One side holds a vacuum, while the other contains one mole of an ideal gas at 298 K. If the partition is ruptured, what happens to the final temperature of the gas___________________?
Show answer Hide answer
Answer: B. Will be 298 K
The expansion is into a vacuum inside a rigid, perfectly insulated vessel, so no heat enters or leaves and no work is done against an external pressure. For an ideal gas internal energy depends only on temperature, so wi...
Q6. Which specific temperature of moist air is not directly measured using a standard psychrometer__________________?
Show answer Hide answer
Answer: A. Dew point
Dew point is a calculated thermodynamic property rather than a direct psychrometer measurement. Standard psychrometers measure dry-bulb and wet-bulb temperatures using exposed and wetted thermometers. Dew point temperatu...