^1920Consider a pan of water being heated (a) by placing it on an electric range and (b) by placing a heatingelement in the water. Which method is a more efficient way of heating water? Explain.Baseboard heaters are basically electric resistance heaters and are frequently used in space heating. Ahomeowner claims that her 5-year-old baseboard heaters have a conversion efficiency of 100 percent. Is thisclaim in violation of any thermodynamic laws? Explain.Is an isothermal process necessarily internally reversible? Explain your answer with an example.Does the cyclic integral of heat have to be zero (i.e., does a system have to reject as much heat as it receivesto complete a cycle)? Explain.Briefly describe a ramjet engine and its application.Which of the following is the correct statement?abCdAll engines are designed as reversible to obtain maximum efficiencyThe increase in entropy is obtained from a given quantity of heat at a low temperatureThe entropy represents a maximum amount of work obtainable per degree drop in temperatureThe change in entropy may be regarded as a measure of the rate of the availability of heat fortransformation into workefgThe efficiency of an ideal Carnot cycle depends onworking substanceon the temperature of the source, onlyon the temperature of both the source and sinkabCdon the temperature of the sink, onlyeon the construction of an engineIn a reversible cycle, the entropy of the systemabCdeabсeKelvin-Plank's law deals withconservation of energyconservation of heatconservation of massabWhich of the following statement is correct according to Clausius statement of the second law ofthermodynamics?It is impossible to transfer heat from a body at a lower temperature to a body at a highertemperatureIt is impossible to transfer heat from a body at a lower temperature to a body at a highertemperature without the aid of an external sourceAll the reversible engines have the same efficiencyAll the reversible and irreversible engines have the same efficiencyIrreversible engines have maximum efficiencyabCdCIt is possible to transfer heat from a body at a lower temperature to a body at a higher temperatureusing a refrigeration cycleeNone of the answersThe mechanical efficiency of a gas turbine plant as compared to internal combustion reciprocating engine ishigherlowersameсdincreasesdecreasesdoes not changefirst increases the decreasesdepends on the properties of the working substanceabCdconversion of heat into workconversion of work into heatThe thermal efficiency of a gas turbine plant as compared to a Diesel engine plant isabefCdunpredictableThe work ratio of a closed cycle gas turbine plant depends on thepressure ratio of the and specific heat ratiotemperature ratio of the cycle and specific heat ratiohigherlowersameunpredictableonly the temperature ratioonly the specific heat ratioIn a two-stage gas turbine plant, with reheating after the first stageabpressure ratio, temperature ratio and specific heat ratioonly the pressure ratiodecreases the thermal efficiencies.increases the thermal efficiencies.does not affect thermal efficiencies.Decreases the work ratio.increases the work ratio.does not affect the work ratio.

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19 Consider a pan of water being heated (a) by placing it on an electric range and (b) by placing a heating element in the water. Which method is a more efficient way of heating water? Explain. Baseboard heaters are basically electric resistance heaters and are frequently used in space heating. A homeowner claims that her 5-year-old baseboard heaters have a conversion efficiency of 100 percent. Is this claim in violation of any thermodynamic laws? Explain. Is an isothermal process necessarily internally reversible? Explain your answer with an example. Does the cyclic integral of heat have to be zero (i.e., does a system have to reject as much heat as it receives to complete a cycle)? Explain. Briefly describe a ramjet engine and its application. 20 Which of the following is the correct statement? a b с d f All the reversible engines have the same efficiency All the reversible and irreversible engines have the same efficiency Irreversible engines have maximum efficiency All engines are designed as reversible to obtain maximum efficiency The increase in entropy is obtained from a given quantity of heat at a low temperature The entropy represents a maximum amount of work obtainable per degree drop in temperature

19 Consider a pan of water being heated (a) by placing it on an electric range and (b) by placing a heating element in the water. Which method is a more efficient way of heating water? Explain. Baseboard heaters are basically electric resistance heaters and are frequently used in space heating. A homeowner claims that her 5-year-old baseboard heaters have a conversion efficiency of 100 percent. Is this claim in violation of any thermodynamic laws? Explain. Is an isothermal process necessarily internally reversible? Explain your answer with an example. Does the cyclic integral of heat have to be zero (i.e., does a system have to reject as much heat as it receives to complete a cycle)? Explain. Briefly describe a ramjet engine and its application. 20 Which of the following is the correct statement? a b с d f All the reversible engines have the same efficiency All the reversible and irreversible engines have the same efficiency Irreversible engines have maximum efficiency All engines are designed as reversible to obtain maximum efficiency The increase in entropy is obtained from a given quantity of heat at a low temperature The entropy represents a maximum amount of work obtainable per degree drop in temperature

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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