1/22/2015MADE EASY ONLINE TEST SERIES Jitendra Yadav (Enroll User) Log Out HOME SCORE CARD MY TEST COMPARE YOUR SELF TIME MANAGEMENT QUESTIONS REPORT DIFFICULTY LEVEL SOLUTION TOPIC REPORT MY PROFILE Solution Report For THERMODYNAMICS REPORTS Represent whole test solution with correct and incorrect answers. BUY PACKAGE View Your Test Analysis NEWS Q. No Question Status Q.1 In a new temperature scale °X, the boiling and freezing point of water at one atmosphere are 200°X and 100°X respectively, is corrected with centigrade scale. The reading 0°X on the centrigrade scale (in °C) is a. 100 b. – 100 c. 250 d. – 150 Attempt Correct Correct Ans. b Solution Q.2 a. 1 , 2, 5 and 6 b. 5, 6, 7 and 8 c. 1, 2, 3 and 8 d. 1, 2, 3 and 4 http://m6.onlinetestseriesmadeeasy.in/madeeasy/index.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 1/12 the volume at the end of expansion is 0.812 Attempt Correct Correct Ans. a Solution Q. 0. The rate of heat rejection to the environment is 5 kW.4 During steady flow compression process of a gas with mass flow rate of 2 kg/s. 0. If the expansion process is isothermal.1 × 10–3 c. 9. The rate of entropy production (W/K) inside the gear box is a. 10 × 10–3 http://m6. b Solution Q. the rest being lost due to friction etc.3 A gas expands from pressure P1 to pressure . The gear box surface is at an average temp.1/22/2015 MADE EASY ONLINE TEST SERIES Attempt Incorrect Your Ans. of 57°C and looses heat to the surroundings at 27°C. The power (in kW) needed to drive the compressor is a. The input shaft receives 55 kW from a prime mover and transmits 52 kW to the output shaft.4] a.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 2/12 . is 2 kJ/kg.in/madeeasy/index.316 b.5 m3 . a Correct Ans.E.10 d. If the expansion process is adiabatic.50 c. increase in specific enthalpy is 15 kJ/kg and decrease in K. a Solution Q.1 d. 34 d.onlinetestseriesmadeeasy. 0. 0.5 The gear box of a machine is operating under steady state. 9. 31 b. 39 c. 10 b. the volume (in m3 ) at the end of expansion will be closer to [Take γ for gas = 1. 21 Attempt Correct Correct Ans. Constant enthalpy c. d Correct Ans. b c. a Solution Q.onlinetestseriesmadeeasy. Attempt d Correct Correct Ans. Free expansion d. The process that occurs can be called ___________ process. c d. a Correct Ans. d Solution Q. Oncethrough boilers never have a steam drum R.6 Match the ListI (Equipment in the refrigeration) with ListII (Purpose) and select the correct answer from the codes given below the lists: a.in/madeeasy/index. a b. Two constant entropy lines cannot intersect Q. Constant internal energy b. a.7 Two insulated tank containing ideal gases at different pressures and temperatures are connected to each other and gases are allowed to mix. The suction pipe diameter of a refrigerator plant should be less than http://m6.1/22/2015 MADE EASY ONLINE TEST SERIES Attempt Incorrect Your Ans.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 3/12 .8 Consider the following statements: P. Attempt Reversible adiabatic Incorrect Your Ans. c Solution Q. In a centrifugal compressor the axial component of the fluid velocity produces rotational effect on the rotor S. The clearance volume of reciprocating compressor is given as a percentage of stroke volume. from B to A c.in/madeeasy/index.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 4/12 . and R b. http://m6. and T d. Q.onlinetestseriesmadeeasy. b Solution Q. R and S Not Attempt Correct Ans. P. b. P. the direction of flow of air in the duct a. S and T c.1/22/2015 MADE EASY ONLINE TEST SERIES the discharge pipe diameter.10 The mathematical conditions at the critical point for a pure substance would be a. c Solution Q. air will not flow in the duct d. The pressure and temperature of the air measured at two different stations are as follows: Considering air as an ideal gas. None of the above Attempt Correct Correct Ans. Which of the above statements are correct? a. T. Q. R.9 Air is flowing steadily through a thermally insulated duct. Q. from A to B b. 88 d.onlinetestseriesmadeeasy. 1. c Correct Ans. and it is found that internal energy decreases by 12 kJ. During this time.4m3 .13 The internal energy of a certain system is a function of temperature alone and is given by formula E = 25 + 0. How much energy was transferred as heat (in kJ) to the gas in this process. d.0667. a Solution Q.12 A 1000 Ω resistor carrying a current of 10 A for 2 sec is kept at a constant temperature of 27°C by a stream of cooling water. 112 c.75 kNm. Entropy change of the universe is ________ J/K.00 Solution Q.in/madeeasy/index. Attempt Incorrect Your Ans. the heatinteraction per degree temperature increase is _________ kJ. Attempt Incorrect Your Ans.1/22/2015 MADE EASY ONLINE TEST SERIES c. –88 Attempt Correct Correct Ans.11 5 kg of gas is compressed in a device from a volume of 1. 26 Correct Ans. –112 b. Attempt Correct Correct Ans. the pressure remains constant at 200 kN/m2 . d Solution Q. 666.14 http://m6.2) Solution Q. If this system execute a process for which the workdone by it per degree temperature increase is 0.67 (666.9m3 to a volume of 1.25 t kJ. a.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 5/12 . 6 kJ/kg respectively.29 (96. T1 ) to the state ‘2’ (P2 .4 b. 224. The temperature (°C) at which water boils in the cooker is a. During the flow change in enthalpy and kinetic energy are 110. 177 (176178) Solution Q. V2 . 400. The latent heat of vaporization of water is 2257 kJ/Kg at 100°C and 101. V1 .6) Solution Q.6 c.in/madeeasy/index.04 m3 capacity is to be used to store air at 100 bar. Solution Q.8) Your Ans.15 Correct Ans.5 (2.16 Air enters a compressor in steady flow manner at 140 KPa and 17°C and leaves it at 350 KPa and 127°C. The flask is to be protected against excessive pressure by a fusible plug which will melt and allow the air to escape if the temperature rises too high. T2 ) in a reversible nonflow process as defined below (a) A constantpressure process followed by a constantvolume process (b) A constantvolume process followed by a constantpressure process Workdone ratio of the above two processes is _________. 27°C. The temperature at which fusible plug must melt in order to limit the pressure of a full flask to a maximum of 150 bar is ______ (°C).17 The weight placed on the steam exhaust port of a domestic pressure cooker never allows the pressure to build up above 250 KPa inside the cooker.1/22/2015 MADE EASY ONLINE TEST SERIES A steel flask of 0. The minimum reversible work input required is ________ kJ/kg. [Take air as perfect gas and R = 287 J/kgK] Attempt Correct Correct Ans.897. 514.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 6/12 .42. 2.6 http://m6. 114. [Given: Environment temperature is 7°C] Attempt Incorrect 97.15 A system expands from state ‘1’ (P1 .onlinetestseriesmadeeasy.55 kJ/kg and 3. if Attempt Correct Correct Ans.325 KPa. 5 c.48 d.in/madeeasy/index. d Solution Q. 18. 15.18 A heat engine receives half of its heat supply at 1000 K and half at 500 K while rejecting heat to a sink at 300 K. 50 b.0 kJ/kgK for air] a. 46. What is the maximum possible power output (in kW) from such a wind mill for a steady air velocity of 36 kmph.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 7/12 .10 Not Attempt Correct Ans. If the area ratio of the nozzle is 4 : 1.2 Not Attempt Correct Ans. if the diameter of its blades is 10 m? [Assume air is at 27°C and 101 kPa. d Solution Q. and nozzle efficiency is 80%. d Solution Q. Take R = 287 J/kgK] a.1/22/2015 MADE EASY ONLINE TEST SERIES d. 84.2 b.18 c. 45 c. 55 Attempt Correct Correct Ans.20 Air enters an adiabatic nozzle at 20 bar and 50°C with a velocity of 80 m/s and leaves with a velocity of 300 m/s. 14. What is the maximum thermal efficiency (in %) of the heat engine? a.12 b. 52.onlinetestseriesmadeeasy.6 Not Attempt Correct Ans. 65 d.6 d. The exit pressure (in bar) of the air is [Take Cp = 1. 127. 16. c Solution http://m6. 92.19 A wind mill is being used to generate pollution free power from the kinetic energy of wind. 18 Not Attempt Correct Ans. then the maximum work (in MJ) that can be obtained from this air is a. b Solution Q.onlinetestseriesmadeeasy.24 http://m6. 326. causing the piston to rise and to compress the spring until the volume inside the cylinder doubles. 426. If the environment conditions are 100 kPa and 300 K. a Solution Q. 120.25 m2 . 19596. a linear spring that has a spring constant of 150 kN/m is just touching the piston but exerting no force on it.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 8/12 . The rate of heat transfer (in kJ/s) to the rods in the oven is a.23 A 250 m3 rigid tank contains compressed air at 1 MPa and 300 K. At this state.22 b. 15 d.22 Long cylindrical aluminium rods (ρ = 2700 kg/m3 and Cp = 0. 29 d.21 A piston cylinder device contains 0.6 b.973 kJ/kgK) of 5 cm diameter are heat treated from 20°C to an average temperature of 400°C by drawing them at a velocity of 10 m/min through a long oven. Now heat is transferred to the gas. then the total workdone (in kJ) by the gas will be a. a Solution Q. 53 d. If the crosssectional area of the piston is 0. 12 b. 350646.76 c.in/madeeasy/index. 14 c.22 Not Attempt Correct Ans.7 Not Attempt Correct Ans.05 m3 of gas initially at 180 kPa.6 c. 350.1/22/2015 MADE EASY ONLINE TEST SERIES Q. in/madeeasy/index.2 Δt kJ/kg (Here Δt is in °C). a Correct Ans. d Solution Q.onlinetestseriesmadeeasy. On pressure volume coordinates. (iii) Isobaric compression to its original volume with heat rejection of 400 kJ/kg.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 9/12 . 70 kJ and 70 kJ/kg d. c Solution Q. 35 kJ and 70 kJ/kg c. 140 kJ and 140 kJ/kg b. (ii) Adiabatic expansion to its original pressure with loss of 140 kJ/kg in internal energy. 70 kJ and 35 kJ/kg Attempt Incorrect Your Ans. 0. the above cycles are best http://m6.1/22/2015 MADE EASY ONLINE TEST SERIES A Lenoir cycle comprises the following processes: (i) Isochoric heat addition of 470 kJ/kg.25 What will be the temperature rise (in °C) due to water falling over a height of 1000 m? Change in internal energy of water is related to the temperature change by equations. [Assume water comes to rest after falling) a. 4.6 b.ΔU = 4. Attempt 2.26 Two heat engine cycles (1 – 2 – 3 – 1 and 1′ – 2′ – 3′ – 1′) are shown below on T – S coordinates. 23 c.23 d.3 Correct Correct Ans. What will be the overall heat transfer and workdone during the cycle respectively? a. The thermal efficiency (in %) of the engine is a.2 b.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 10/12 . c.2 http://m6.27 A reversible heat engine operates with three thermal reservoirs and delivers 50 kW power.onlinetestseriesmadeeasy. d. b. 15.1/22/2015 MADE EASY ONLINE TEST SERIES represented as: a. Attempt Correct Correct Ans. 8. d Solution Q. The temperature of the other reservoirs are 400 K and 300 K. The engine absorbs 1000 kJ/s from a reservoir at 600 K.in/madeeasy/index. and the rate of heat transfer through the wall is 1500 watt. 27.2 d.onlinetestseriesmadeeasy. the temperature of the inner and outer surfaces of the brick wall are measured to be 25°C and 9°C.28 The ratio of work input needed to isentropically compress the saturated steam from 1 bar to 5 bar and work input needed to isentropically compress the saturated water for the same pressure ratio is _________. On a day when the temperature of the outdoors is 7°C and the indoor temperature is maintained at 27°C. d Solution Q. Attempt Incorrect 0.7) Solution Q.7 Attempt Correct Correct Ans.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 11/12 .37.5 (7. respectively. Solution Q. 800 (799801) Solution Q. 75 Correct Ans. The iron block eventually reaches thermal equilibrium with the lake water.37) Your Ans.30 Considering steady heat transfer through a 10 m × 15 m brick wall of a house of thickness 50 cm. [Assume surrounding air is at 27°C and Cv for air = 0.340. 2.1/22/2015 MADE EASY ONLINE TEST SERIES c.in/madeeasy/index. The exergetic efficiency of the process is ________ %. 7.72 kJ/kg°C] Not Attempt Correct Ans. Attempt Correct Correct Ans. A paddle wheel inside the tank is rotated by an external motor till the temperature rises to 77°C. Rate of total entropy generation associated with this heat transfer process is ________ W/K. Assuming on average specific heat of http://m6.31 A 100 kg block of iron casting at 500 K is thrown into a large lake that is at a temperature of 285 K.357 (0.29 A rigid insulated tank contains 1 kg of air at 2 bar and 27°C. 2) Solution Q.72 (5772.33 A 1200 kg vehicle travelling at 90 km/hr impacts a plunger attached to a pistoncylinder arrangement. each filled with 50 kg of air. the entropy generated during the process is ______ kJ/K.801. produces work. 5772. Not Attempt Correct Ans. Not Attempt Correct Ans.php?pageName=timeManagementReport&testid=50&t=cont1&testType=2 12/12 .in/madeeasy/index.1/22/2015 MADE EASY ONLINE TEST SERIES 0.87 (1.65 (8. Maximum work obtained from the tank is ________ kJ.9375 Correct Ans. Solution http://m6.09.onlinetestseriesmadeeasy. The maximum temperature rise of the liquid is ________ °C. 8. and rejects heat to the low temperature tank. The specific heat of the liquid is 4.2) Solution Q.05773. If all of the energy of the vehicle is absorbed by the 100 kg of liquid contained in the cylinder. Attempt Incorrect 1. A heat engine placed between the two tanks extracts heat from the high temperature tank. have temperature of 900 K and 300 K. .0 kJ/kg°C.45 kJ/kgK for the iron.94) Your Ans.32 Two rigid tanks.