What is the change in internal energy equal to in reciprocating steam engines__________________?
Show answer Hide answer
Answer: A. work done during the rankine cycle ;
Explanation
Reciprocating steam engines convert thermal energy into mechanical work through idealized thermodynamic cycles. In standard Rankine cycle analysis, energy balances equate the net work output to changes in cycle states. Internal energy variations correspond directly to the net work performed during the expansion and compression phases. The Rankine cycle is the theoretical thermodynamic framework used to model steam power plant systems. First law of thermodynamics relates heat added, work done, and changes in internal energy. Reciprocating engines use expanding steam against a piston to generate mechanical shaft power.
Thermodynamic efficiency calculations for steam engines rely on accurate cycle work evaluations. Historical locomotive development depended on improving the Rankine cycle efficiency of steam engines. Engineers analyze pressure-volume indicator diagrams to determine actual work output in reciprocating machines. Option B limits the scope exclusively to compression work, ignoring the primary expansion energy conversion. Option C focuses solely on adiabatic expansion while omitting the complete cycle work balance. Option D confuses internal energy change with enthalpy change across specific flow processes.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. What variables are plotted on true stress-strain diagrams for engineering materials__________________?
Show answer Hide answer
Answer: B. load/instantaneous cross-sectional area original area and log
True stress-strain diagrams plot true stress based on instantaneous cross-sectional area against natural logarithmic strain increments. Using instantaneous area accounts for the continuous reduction in specimen cross-sec...
Q2. What is the approximate capillary height of water at 20°C inside a clean glass tube with a 1 mm bore____________________?
Show answer Hide answer
Answer: E. 30 mm
Capillary action causes water to rise inside small-diameter glass tubes due to the adhesive forces between water and glass. Surface tension forces pull the liquid column upward until the weight of the water column balanc...
Q3. What is the typical metallic composition of silver solder ___________________?
Show answer Hide answer
Answer: A. silver, copper, zinc
Silver solder is a brazing alloy primarily composed of silver, copper, and zinc to lower melting points and improve joint strength. Adding copper and zinc to silver creates a ternary alloy system with a significantly low...
Q4. Typically, how much coal is consumed per kWh generated in a standard thermal power plant__________________?
Show answer Hide answer
Answer: C. 0.6 to 0.8 kg
Standard coal-fired thermal power plants typically consume around zero point six to zero point eight kilograms of coal per kilowatt-hour. Thermodynamic losses in boilers, steam turbines, and electrical generators dictate...
Q5. What is the typical compression ratio range for standard passenger car engines___________________?
Show answer Hide answer
Answer: B. 7
The compression ratio of an internal combustion engine compares cylinder volume at bottom dead center to top dead center. Standard passenger car gasoline engines are designed with compression ratios ranging typically bet...
Q6. What is the maximum allowable ash content percentage in diesel oil_______________?
Show answer Hide answer
Answer: E. 0.001%
Diesel fuel specifications restrict ash content to extremely low levels, typically a maximum of 0.001%, to prevent fuel system wear. Excessive ash-forming mineral compounds in diesel oil can cause abrasive wear on precis...