Questions Is heat transfer the only way to get rid of entropy? – False The entropy is proportional to the part of any energy unit that can be converted into work? - False The entropy of any general system can only increase or stay constant? - False The entropy creation in a system can only be positive or null? - True Heat is a state function? - False The work transmitted to the rod of an expanding piston engine is f PdV ? - False Assuming a perfect mechanism without friction could a Carnot engine be built? - False The total pressure can be measured by a hole with an axis perpendicular to the flow? - True The velocity of sound of a known perfect gas can be calculated by using only a temperature measure True The velocity of sound in an adiabatic channel of constant section can only be reached at its extremity? True The pressure ratio required to reach the sonic velocity has the same value for all perfect gas – False favr F'iel The maximum gas flow in a safety valve with a very large pressure difference can be directly calculate pressure ratio between the inner pressure and the atmosphere? True A supersonic flow of Mach 3 can be reached in simply converging nozzle? False Neglecting the bearing losses, the isentropic efficiency of an adiabatic perfect gas compressor is the r specific work required along an isentropic process and the specific work provided at the shaft? True The polytropic efficiency of a compressor or a turbine accounts only for the dissipation losses? True The polytropic and isentropic efficiencies of a turbine are the same? False Policy and Regulatory Obstacles: In the absence of supportive policies and regulations, the expansion of renewable energy can be hampered. Sri Lanka may lack incentives, subsidies, and explicit guidelines for renewable energy projects, reducing the country's appeal to investors. Dependence on Fossil Fuels: Sri Lanka may rely extensively on conventional fossil fuels for its energy requirements, making the transition to renewables challenging. Existing infrastructure and investments in power generation using fossil fuels may delay the transition to cleaner alternatives.
