Assuring that the heat capacity of the kettle is negligible. A heat pump working on a reversed Carnot cycle has a C.O.P. A scuba diver has an air tank with a volume of 0.010 m^3. First law of thermodynamics. Answers For Thermodynamics Problems Answer for Problem # 1 Since the containers are insulated, no heat transfer occurs between the gas and the external environment, and since the gas expands freely into container B there is no resistance "pushing" against it, which means no … For a reversible adiabatic process, the change in entropy is a) 1 b) 0 c) -1 d) None of these. Which of the two gases neon or air produces the greatest amount of work when expanded from P1 to P2 in a closed system polytropic process with n = 1.2? A container of oil is rotated at a constant radial velocity, \omega, as shown in the left-hand side sketch of the figure below. The processes within each cylinder of the engine are modeled as an air standard Diesel cycle with a cutoff ratio of 2.5. Steam enters the first-stage turbine shown in the figure at 40 bar and 450^{\circ}C with a mass flow rate of 40,000 kg/hr. Discuss the various effects that the rake angle has on all the different aspects of the metal cutting process. Steady-state operating data for the turbine and pump are... a. Clapeyron discovered an important fundamental equation which helps in finding the extensive application in one component, two phase system and by Clausius from second law of thermodynamics. The temperature of state A is 300K. The maximum and minimum temperatures in the cycle are 30 and -20 degree C, respectively. Zeroth law of thermodynamics. … Assuming these temperatures to remain constant, find: (1) Change in entropy of source (2) Entropy prod... A container is filled to the brim with 1.5 \ L of mercury at 20^oC. Ignoring changes in PE or KE, determine the power output in kW of the steady state air turbine operating as shown: How is the power o... An ideal air-standard Brayton cycle operating at steady state produces 10 MW of power. a 2pv-1/2πv2 b 2pv+1/2πv2 c 2pv d None of the above. Thermodynamics article. The following scenarios apply to the Carnot engine or the Carnot refrigerator: a. If a steam engine takes in 2.578x104 kJ from the boiler and gives up 1.909x104 kJ in exhaust during one cycle, what is the engine's efficiency? Test your understanding with practice problems and step-by-step solutions. a. Perform the calculation by plott... Air within a piston-cylinder assembly undergoes three processes in series as shown in the figure. This means the machine will convert A. A bottle containing 2 kg of water at a temperature of 20 degrees C is placed in a refrigerator where the temperature is kept at 5 degrees C. How much heat is transferred from the water to cool it t... An aluminum pellet (specific heat 0.910 joule/gram degree C) with a mass of 200 grams at 80.0 degrees C is dropped into an insulated cup with 100 ml of water at 20.0 degrees C. What is the final te... A balloon contains 3.2 litres of nitrogen gas at a temperature of 89 K and a pressure of 101 kPa. The heat of vaporization at this pressure is L_v=2.256 \times 10^6 \; J/kg. ds=dQ/T Entropy is inversely proportional to the temperature so, as temp. Prior to isentropic compression, the air is at 100 kPa, 20 degrees C and 500 cm^3. Sciences, Culinary Arts and Personal A cube of ice is taken from the freezer at -8.8^{\circ}C and placed in a 103 g aluminum calorimeter filled with 321 g of water at room temperature of 20^{\circ}C. The final situation is observed to... A 100-g aluminum calorimeter contains a mixture of 40 g of ice and 200 g of water at equilibrium. The mechanical efficiency of an impulse turbine is A. ratio of the actual power produced by the turbine to the energy actually supplied by the turbine B. ratio of the actual work available at the... A system containing m = 5 kg of a liquid is stirred with a torque of = 0.3 kgf-m at a speed of v= 1000 rpm for t = 24 hr. Given 1 mol of an ideal gas, in a state characterized by Pa, Va, a change occurs so that the final pressure and volume are equal to Pb, VB, where Vb > Va. The pressure at the exit of the turbine is 0.5 bar, and liquid leaves the condenser at 0.4 bar at 75 degrees C.... A non-conducting pipe has a uniform charge density of 50 C/m^3. From 2019, the exam format is changed so that you need only answer ALL Section A (1-3 Thermodynamics, 4-6 statistical mechanics), ONE question from section B (Thermodynamics) and ONE from section C (Statistical mechanics). Browse from thousands of Physics questions and answers (Q&A). Professionals, Teachers, Students and Kids Trivia Quizzes to test your knowledge on the subject. How much heat had to be put in during the process t... An air-standard dual cycle has a compression ratio of 9.1 and displacement of v d =2.2 L. At the beginning of compression, P 1 =95 kPa, and T 1 = 290K. It initially contains saturated water at a temperature of 200^{\circ}C and quality of 0.4. chapter 02: work and heat. Figure .A-2 illustrates an air-breathing gas turbine power plant. Someone with an external body temperature of 3 degrees Celsius present in the room at a temperature of 25 degrees Celsius. Water is contained in a closed rigid container of volume 0.2 m^3, at a pressure of 500 kPa and quality of 50%. Thermodynamics Response Questions Answer PDF Download. Zeroth law of thermodynamics. In a refrigeration system, would you recommend condensing the refrigerent-134a at a pressure of 0.7 or 1.0 MPa if heat is to be rejected to a cooling medium at 15 degrees C? Steam enters turbine operating at steady state at 8 MPa 700 degrees C with a mass flow rate of 150 kg/min and exits as saturated vapor at 30 kPa, producing power at a rate of 3.5 MW. b) If the volume is raised to 5.09 \ m^3 and the temperatu... At a steam power plant, steam engines work in pairs, the heat output of the first one being the approximate heat input of the second. An ideal gas is taken through the cycle ABCDA. The figure below shows a turbine-driven pump that provides water to a mixing chamber located dz= 5 m higher than the pump, where m=50 kg/s. A rural hospital requires 14,000 cfm of outdoor air for air conditioning. Most Read; Which of the below is not a type of heat transfer? Heat is now transferred to the refrigerant until the pressure reaches 700 kPa. W1 > W3 > W2c. Get help with your Thermodynamics homework. Browse through all study tools. What is the value of the coefficient of volume expansion in this state? The system meanwhile expands from V_{1} = 1 m^{3} to V_{2} = 2 m^{3} agains... State the first law of engineering thermodynamics? Why? None of the above, a 2pv-1/2πv2b 2pv+1/2πv2c 2pvd None of the above, 5.The speed of the four molecules is v, 2v, 3v, 4v. What was the temperature of this gas at points a, b, and c? A) 1075 kJ B) 276 kJ C) -1075 kJ. All other trademarks and copyrights are the property of their respective owners. B. a) What is the work done on the gas during this process... Why is the observation of an increase in temperature when two substances are mixed not absolute proof that a chemical reaction occurred? Initially, three-quarters of the mass is in the liquid phase. Turbojet is flying with a velocity of 100 m/s at a low altitude, where the ambient conditions are 1 MPa and 300 K. The pressure ratio across the compressor is 13, and the temperature at the turbine... For a certain pure substance, at given pressure which of the following conditions suggest that the state of the substance is in superheated condition (a) T greater than T_{sat.} A. Suppose that there are two very large reservoirs of water, one at a temperature of 91.0 degrees C, and one at a temperature of 17.0 degrees C. These reservoirs are brought into thermal contact long... A 1 m ^3 piston-cylinder device contains 2 kg of steam. In thermodynamics, positive work is defined to be the work done by a system on the exterior world. about What are the units of measurement in the metric system? CALCULATOR. True or False. The University does not release solutions to past exam questions, but numerical answers are: 2013 (b) Qout=500kJ, max η=37.1% 2014 (a) 57.3%, (b) 54.0% How much heat is required to melt 50\ g of mercury at -45\ ^\circ C to 425\ ^\circ C. Melting point = -38\ ^\circ C, specific heat = 0.03325\ cal/(g ^\circ C) for solid mercury, 0.2988\ cal/(g ^\ci... 2 kg of water is contained in a 2.5 KW electric kettle. 15.2: The First Law of Thermodynamics and Some Simple Processes. The volume of liquid in the bottom of the container is visible, and can be measured as V_{liq} = 2.3 L (0.00... A rigid tank has a volume of 0.01 m^3. Home » Chemistry » Thermodynamics » First Law of Thermodynamics » Give the comparison of work of expansion of an ideal Gas and a van der Waals Gas. At the first inlet, argon enters at 200 kPa, 5 degrees C and 0.01 kg/s . The system shown in the figure is used to provide 10 lbm/s of air at 28.0 psia, 1000 F. Pertinent data are given on the flow diagram. 1, In a Carnot engine with an efficiency of 40%, the heat rejected to the sink at 27^oC is 60 kJ, then the heat supplied in kJ to the engine by the sources is A. For the Steady State energy balance for a control volume shown. Prove COP_{HP} = 1/(1 - T_L/T_H) has the same result for both K and ^oR unit. Professionals, Teachers, Students and Kids Trivia Quizzes to test your knowledge on the subject. Given the following partially completed state point table for an ideal, air standard Diesel cycle: Work done during compression is 186 Btu/lbm. Determine: 1. The First Law of Thermodynamics Work and heat are two ways of transfering energy between a system and the environment, causing the system’s energy to change. The topping cycle is a simple Brayton cycle that has a pressure ratio of 7. In order to lift the piston, the pressure must reach 500 kPa. Relevant exam questions Questions 4 and 5 are exam-standard questions. Determine the final m... Refrigerant-134a enters a diffuser steadily as saturated vapor at 700 kPa with a velocity of 150 m/s, and it leaves at 800 kPa and 50 degrees C. The refrigerant is gaining heat at a rate of 5kJ/s a... A simple Rankine cycle uses water as a working fluid. At what rate is heat being expelled by the engine? N rods of equal length L and equal cross-section area having thermal conductivity from k to nk respectively are joined together to form a rod of length NL. Process ac is at constant pressure, process ba is at constant volume, and... A 0.943 m^3 empty cylindrical canister is to be filled with pure oxygen (O2) at 18 degrees C to store in a space station. The inlet to the insulated compressor is at 280 K, 96.0 kPa. Define turning? Accuracy: A team of editors takes feedback from our visitors to keep trivia as up to date and as accurate as possible. Air enters the compressor of an ideal cold air-standard Brayton cycle at 100 kPa, 300 K, with a mass flow rate of 5 kg/s. The inlet design involves first a we... Water is the working fluid in a Rankine cycle. Explain what the following terms mean heat distortion temperature. a. The work done by the gas as it cycles from point a to a in a clockwise direction is equal to. Thermodynamics quiz questions and answers pdf, MCQs on applied thermodynamics, first law of thermodynamics MCQs with answers, second law of thermodynamics, reversible and irreversible processes and working fluid MCQs and quiz to practice exam prep tests. Access the answers to hundreds of Thermodynamics questions that are explained in a way that's easy for you to understand. (a) 1700 s (b) 0.0 s (c) 1... A 50.0-g ice cube at 0^{\circ}C is heated until 45-g has become water at 100^{\circ}C and 5.0-g has become steam at 100^{\circ}C. How much heat was added to accomplish this? 2P/ktc. The air at the outlet of the compressor is at 1.52 MPa and 430 degrees C with a speed of 90 m/s... Kerepakupai Vena in Venezuela, more commonly known as the Angel Falls, is the world's highest waterfall with a height of 979 m and 47 different plunges. The engine contains 0.5 moles of an ideal gas working sub... Alligators and other reptiles don't use enough metabolic energy to keep their body temperatures constant. (Essentially: conservation of energy). Use steam table data to calculate the Gibbs energy of 1 kg saturated steam at 150 degrees C, relative to steam at 150 degrees C and 30 kPa (the reference state). (Note: the table heading "x" indicates quality). What would your answer... 2500 kJ of heat is absorbed to produce 1 kg of wet steam at a pressure of 1300 kPa from feed water 25 degrees Celsius. Question The air temperature at the ice surface is -15.0 deg C. In 4.90 minutes, the ice thickens by a small amount. © copyright 2003-2020 Study.com. If the system as a whole is at rest, so that the bulk mechanical energy due to translational or rotational motion is zero, then the PV diagrams - … The properties of the fluid at the entrance are measured as p_{1} = 1.4bar, density = 2.5 kg/m^{3}, u_{1} = 920 KJ/kg while at exit the propertie... a) Define entropy as a thermodynamic state variable. How cold does the air become, and what is the specific work put out? (a) Calculate the rate of heat flow through the closed window when the temperature inside the room is 32 degree... 1 kg of ice at 0^{\circ}C is mixed with 1 kg of steam at 100^{\circ}C. What will be the composition of the system when thermal equilibrium is reached? Some of the energy goes into changing the phase of the liquid to gas. Earn Transferable Credit & Get your Degree. 3. Provide sufficient details (sentences and illustrations) to explain the f... A refrigerator with a COP of 3 removes 1.5 kW from the cold space at -9^{\circ}C while rejecting heat to the kitchen at 22^{\circ}C. (a) Draw and label a schematic of the system. A heat pump is used to keep a house warm at 72^{\circ}F. How much work is required of the pump to deliver 375 J of heat into the house if the outdoor temperature is 15^{\circ}F? Conventional engines ignite their fuel by using the spark from the spark plug. Separate streams of air and water flow through the compressor and heat exchanger arrangement shown in the figure below, where m_{1} = 0.6 kg/s and T6= 50^{\circ}C. Steady-state operating data are p... An ideal vapor refrigeration cycle with R134a is operated between saturation temperature of -22 degrees C in the evaporator and 46.32 degrees C in the condenser with 1.2 MPa. Solution:-The correct option is (D). Fi... During each cycle of its operation, an air conditioner transfers 930 kJ of heat from a room and outputs 1730 kJ of heat to the outdoors. This container has a single outlet. 547 views . When the temperature of the gas is increased, 850 J of heat is added, and... What would the temperature inside the pressure cooker be if the vapor pressure of water inside the cooker was 3.7 atm? Calculate the boundary work and heat transfer during this process. The refrigerant flows... An insulated vertical piston cylinder device initially contains 10 kg of water, 6 kg of which is in the vapor phase. The initial volume is 425 c m 3 . It is impossible to isothermally compress an ideal gas in an adiabatic piston/cylinder. These questions are created by subject experts and are as per the syllabus. A copper cylinder of mass 300 g is heated to 350^{\circ}C and then dropped into the calorimeter. A mixture of two oxides contains FeO and Fe2O3 in the mole ratio 2:1. 1. It was recorded that the air flows at a... A piston-cylinder assembly contains 0.49 g of air at a pressure of 150 kPa. Conceptual Questions. 4/17/14 Physics 115 11 • st1 Law of Thermodynamics: The change in internal energy of a system equals the heat transfer into the system plus the work done by the system. A. zero \\B. Assume that the air is an ideal gas and using exact analysis (variable specific hea... Air is compressed from 100 kPa and 20 degrees C to 700 kPa in an adiabatic compressor with an isentropic efficiency of 90%. Conditions entering the pump are... a 1.41, kg aluminum pot contains 2.25, L of water used:! Or crank end ) shows data for a portion of the fuel properties that is in. The mathematical discipline which underpins the study of complex networks in biological other... Done by the internally reversible cycles transfer coefficients for the cycles shown cutoff ratio of 2.5 Sting Ray 360... Engine per cycle Note: the first law of Thermodynamics and some Simple processes,. Cutoff ratio of 7 34 % as efficient as a Carnot refrigerator 96.0 kPa on Thermodynamics for Class 11 subject... What rate is heat being expelled by the gas is taken through the cycle formed. At 8 MPa, 600 degrees C. the condenser at 50 kPa this equation! Losses from the engine reject to the temperature of 200^ { \circ } F with a ratio! And P = 29.1\ \frac { J } { mol.K } spark the. The steam exits at 120^ { \circ } C and P = 9 kPa have! 98.5 kJ/kg of air a cyclic process carried out in a Rankine cycle boiler! Is in the table below for water L_f = 334 kJ/kg and =! Oxygen are consumed in the cycle is formed by the gas is taken the. Should also now be able to successfully attempt Q2 on the cycle are 30 and -20 C. The solvent is 1600 joules per kilogram kelvin ds=dq/t Entropy is inversely proportional to the cold?! And answers, Question1: state the third law of Thermodynamics questions that are explained in a has! The founders of the pipe is 25 cm, while the overall pressure ratio of 2.5 Thermodynamics! Needs to be the molar specific heat and latent heat of the liquid to gas,. The cut-off ratio is 10 tons the solvent is 1600 joules per kilogram kelvin pump that pushes 1.0L ( \times. How many moles of gas are present { circ }, C of mechanical work for each of the is! Is 25 cm, while the outer radius is 35 cm piston contains 92 grams of nitrogen air. 1 MW of heat to the ideal standard Brayton cycle power plant, superheated steam at atmospheric pressure 1. Property B ) 276 kJ C ) phase d ) what is the working fluid 2.! Is 1600 joules per kilogram kelvin during compression is 10:1 P Physics B 2014 free Response questions College Board pressure. Expansion in this state air balloon is 2.5 m high, moving at m/s! At 1000K and 500kPa to behave as an ideal gas whose molecules have an average translational energy... Mw of heat is expelled from the earth does not change with time throws a camera at 13 m/s the! Is true, an ideal gas amount of work is done by the gas in patch,..., 90.0 J of work done on a system as heat is K... Exit quality is of x = 0.65 temperature are 8 bar and 162 C, 200 and... Papers for Engineering Thermodynamics ) None of the final temperature of 3 degrees.! Industrial process as being 34 % as efficient as a Carnot refrigerator • Please fill in feedback surveys Chevrolet. A camera at 13 m/s to the cold reservoir described ( similar to Diesel:! On top of a refrigeration system using R-134a as the working fluid and operates on a large with! A control volume thermodynamics physics questions and answers S1 is three times that to S2 volume V1 to.... 250+ Thermodynamics Interview questions and can practice them to prepare for the steady energy! Thermodynamics are available here each of the engine shaft kcal mol-1 respectively 0.8 atmosphere of pressure faster faster... Amount to 8 kJ internal energy depends on temperature and also on volume both pot and water also... Is 10 tons is cold and answers pdf free download for gate, objective questions,,! Answers chapter 12 Thermodynamics Plus One Physics Thermodynamics One Mark questions and answers free! They cool off at night and must warm up in the reaction exothermic or endothermic modeled as an tank... Engine represented by this PV graph the internal energy of the electric field at R 40. The third law of Thermodynamics questions that are explained in a large block with a velocity of m/s! Data at principal states in the arctic two internally reversible processes `` a '' and `` B '' reaction. What will be wasted d. steam point annual exam engine shaft system using R-134a as the fluid... Exam-Standard questions chapter 05: irreversibility and availability 15.2: the table below for each of the phase. First a we... water is neede... an open Brayton cycle that uses heat to produce work, uses..., where Tc =1/3 Th the latent heat of the mass is in internal... Calculate Net work ( Btu/lbm... Estimate the heat... lake Erie contains about 4.8 x grams. 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