Chapter 7, Problem 7.8CU

1. The first law of thermodynamics discussesa. Thermal equilibriumb. Energy conservationc. Direction of heat flowd. Entropy is zero at absolute zero temperature 2. A tank contains 1 kg mass gas whose density is 700 kg/m3. The pressure is increased from 1 bar to 3 bar. The approximate specific boundary work of the system isa. Cannot be find since some data is missingb. 285 kJ/kgc. 0 kJ/kgd. 0.285 kJ/kg 3. The nozzle is a device in whicha. Area decreases b. Area increasesc. Velocity decreases d. Velocity increases 4. Choose the correct statement/s with respect to entropy change during a processa. Entropy increases with increase in pressure at constant temperatureb. Entropy increases with increase in temperature at constant pressurec. Entropy can be kept constant by systematically increase both pressure and temperatured. Entropy can not be changed 5. The isentropic process is also called asa. Adiabatic processb. Irreversible adiabatic processc. Reversible adiabatic processd. Reversible…

Which of the following is the correct statement?   a. Irreversible engines have maximum efficiency   b. The increase in entropy is obtained from a given quantity of heat at a low temperature   c. The entropy represents a maximum amount of work obtainable per degree drop in temperature   d. All the reversible engines have the same efficiency   e. All the reversible and irreversible engines have the same efficiency   f. The change in entropy may be regarded as a measure of the rate of the availability of heat for transformation into work   g. All engines are designed as reversible to obtain maximum efficiency

Determine the specific exergy of saturated water vapor at 137 °C, where To = 313K, Po = 101.3kPa. Assume the velocity and elevation is zero with reference to the environment. You must use following tables to solve this problem. (answer to 2 decimal) Saturated water temperature table Sat Liq. Temp., Sat Liq. Sat Liq. Sat Liq. vf uf hf sf °C m3/kg kJ/kg kJ/kg kJ/kg.K 30 0.001004 125.73 125.74 0.4368 35 0.001006 146.63 146.64 0.5051 40 0.001008 167.53 167.53 0.5724 45 0.00101 188.43 188.44 0.6386 Saturated water temperature table Temp., Sat. Vap. Sat. Vap. Sat. Vap. Sat. Vap. hg kJ/kg vg ug sg °C m3/kg kJ/kg kJ/kg.K 125 0.7508 2534.5 2713.5 7.0745 126 0.7358 2535.5 2714.8 7.0649 127 0.7208 2536.5 2716.1 7.0553 128 0.7058 2537.5 2717.4 7.0457 129 0.6908 2538.5 2718.7 7.0361 130 0.6758 2539.5 2720.0 7.0265 131 0.6608 2540.5 2721.4 7.0169 132 0.6458 2541.4 2722.7 7.0073 133 0.6308 2542.4 2724.0 6.9977 134 0.6158 2543.4 2725.3 6.9881 6.9785 135 0.6008 2544.4 2726.6 136 0.5858 2545.4 2727.9…

Figure P6.22 provides the T-s diagram of a Carnot refrigeration cycle for which the substance is Refrigerant 134a. Determine the coefficient of performance.

Thermodynamic Keys Conservation of Mass Questions 71-75 are based on the stated information listed below. A feed water heater operating at steady state has two inlets and one exit. At inlet 1, liquid water at Pi = 7 bar, TI 40°C, vị = 1.0078x10 m/kg enters through an area of AI = 25 em. At inlet 2, water vapor enters at P2 =7 bar, T2 200°C, v=0.2999 m'/kg with a mass flow of 40 kg/sec. Saturated liquid exits at 3 at P, =7 bar, v= 1.108x10 m/kg with a volumetric flow rate of 0.06 m/sec. 71. The mass flow rate at the exit in kg/sec is a. 40.00 b. 14.15 c. 54.15 d. none of the above. 72. The mass flow rate at inlet 1 in kg/sec is 40.00 14.15 a. b. 54.15 c. d. none of the above. 73. The velocity at inlet 1 in m/sec is a. 16.1 b. 5.7 c. 21.8 d. none of the above. 74. The volumetric flow rate at inlet 2 in m/sec is 0.014 0.06 b. 12.00 a. с. d. none of the above. 75. The volumetric flow rate at inlet 1 in m³/sec is a. 0.014 b. 0.06 с. 12.00 d. none of the above.

Answer please

Answer true (T) or false (F) as appropriate1. Entropy is a measure of irreversibilities in processes.2. The entropy of the universe must always decrease.3. The thermal efficiency of a Carnot engine is the maximum possible.4. The gas turbine operates on the Rankine cycle.5. The steam turbine operates on the Brayton cycle.

Multiple choice Questions Question No. 2: When a system is taken from state A to state B through a reversible path 1 and again the system is taken to its initial state A from B through different reversible path 2, then what will be the effect on entropy? a.entropy increasesb.entropy decreasesc. entropy remains constantd. none of the above

An internal combustion engine is a commonly-analyzed thermodynamic system. In a few sentences, describe the flows of energy and matter across the boundaries of a typical engine.