# Gate Model Test 1

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Take this test for testing ur GATE knowledge
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󰁓󰀮󰁋󰀮󰁅󰁮󰁧󰁩󰁮󰁥󰁥󰁲󰁩󰁮󰁧 󰁁󰁣󰁡󰁤󰁥 󰁐󰁲󰁥󰁰󰁡󰁲󰁥󰁤 󰁢󰁹 󰁓󰁒󰁉󰁎󰁉󰁖󰁁󰁓󰁁󰁎󰀮󰁖 1) An engine operates between tempe of 900 K & T 2  and another between For both to be equally efficient, value o a) 600K  b) 700K c) 750K d) 650K 2) A Carnot engine rejects 30% of abs a sink at 30°C the temperature of heat s a) 100ºC  b) 433ºC c) 737ºC d) 1010ºC 3) An engine working on Carnot cycle of absorbed heat from the source, w temperature is maintained at 27°C, the temperature is a) 750ºC  b) 477ºC c) 203ºC d) 67.5ºC 4) An ideal gas at 27°C is heated  pressure till its volume becomes three would be the temperature of gas? a) 81ºC  b) 627ºC c) 543ºC d) 327ºC 5) A reversible engine is shown belo cycle of operation draws 5 MJ fro reservoir and does 840 kJ of work. T Q 2  and Q 3  are a)   Q 2  = + 4.98 MJ ; Q 3  = - 0.82  b)   Q 2  = - 4.98 MJ ; Q 3  = + 0.82 c)   Q 2  = + 4.98 MJ ; Q 3  = + 0.82 d)   Q 2  = - 4.98 MJ ; Q 3  = - 0.82 󰁹 󲀓 󰁇󰁡󰁴󰁥 󰁍󰁯󰁤󰁥󰁬 󰁔󰁥󰁳󰁴 󰀱 󰀨 󰁍󰁥󰁣󰁨 󲀓 󰁔󰁨󰁥󰁲󰁭󰁯󰁤󰁹󰁮󰁡     rature limits 2  & 400 K. f T 2  will be rbed heat to ource is rejects 40% ile the sink n the source at constant times. What w, during a the 400 K he values of J J J J 6) Assigning the basic dimensions time and temperature respectively θ (Temperature), what are the entropy? a) MLT -2 θ  b) ML 2 T -1 θ -1 c) ML 2 T -2 θ -1 d) ML 3 T -2 θ -1  7) Efficiency of a Carnot engine is direction is reversed. COP of the cycle is : a) 1.33  b) 0.75 c) 0.33 d) 1.75 8) A Carnot engine operates bet 27°C. If the engine produces 300 entropy change during heat additio a) 0.5KJ/K  b) 1.0KJ/K c) 1.5KJ/K d) 2.0KJ/K 9) A gas is compressed in a cylin  piston to a volume one half of its During the process, 300 kJ heat lef internal energy remains same. Th the gas is : a) 100KNm  b) 150KNm c) 200KNm d) 300KNm 10) A frictionless piston cylinder d gas initially at 0.8 MPa and 0.015 constant temperature to a final volu The work output in KJ during this pa) 8.32  b) 12.00 c) 554.67 d) 8320.00 󰁭󰁩󰁣󰁳󰀩   󰁐󰁡󰁧󰁥 󰀱 to mass, length, as M, L, T and dimensions of 75% if the cycle reversed Carnot een 327°C and kJ of work, the is der by a marble riginal volume. the gas and the work done on evice contains a 3 . It expands at me of 0.030 m 3 . rocess will be  󰁓󰀮󰁋󰀮󰁅󰁮󰁧󰁩󰁮󰁥󰁥󰁲󰁩󰁮󰁧 󰁁󰁣󰁡󰁤󰁥󰁭󰁹 󲀓 󰁇󰁡󰁴󰁥 󰁍󰁯󰁤󰁥󰁬 󰁔󰁥󰁳󰁴 󰀱 󰀨 󰁍󰁥󰁣󰁨 󲀓 󰁔󰁨󰁥󰁲󰁭󰁯󰁤󰁹󰁮󰁡󰁭󰁩󰁣󰁳󰀩   󰁐󰁲󰁥󰁰󰁡󰁲󰁥󰁤 󰁢󰁹 󰁓󰁒󰁉󰁎󰁉󰁖󰁁󰁓󰁁󰁎󰀮󰁖 󰁐󰁡󰁧󰁥 󰀲 11) The statement that entropy of a pure substance in complete thermodynamics equilibrium becomes zero at the absolute zero of temperature is known as (a) Law of Entropy (b) First Law of Thermodynamics (c) Second Law of Thermodynamic (d) Third Law of Thermodynamics 12) A balloon containing an ideal gas is initially kept in an evacuated and insulated room. The balloon ruptures and the gas fills up the entire room. Which one of the following statements is TRUE at the end of above  process? (a) The internal energy of the gas decreases from its initial value, but the enthalpy remains constant (b) The internal energy of the gas increases from its initial value, but the enthalpy remains constant (c) Both internal energy and enthalpy of the gas remain constant (d) Both internal energy and enthalpy of the gas increase   13) A gas expands in a frictionless piston-cylinder arrangement. The expansion process is very slow, and is resisted by an ambient pressure of 100 KPa. During the expansion process, the pressure of the system (gas) remains constant at 300 KPa. The change in volume of the gas is 0.01 m 3 . The maximum amount of work in KJ that could be utilized from the above process is: a) 0  b) 1 c) 2 d) 3 14) Work done in a free expansion process is a) Positive  b)  Negative c) Zero d) Maximum 15) The dimension of enthalpy is (a) MLT -2 (b) ML 2 T -2  (c)ML 2 T 2 (d) ML 3 T -2   16) A mono-atomic ideal gas (γ = 1.67, molecular weight = 40) is compressed adiabatically from 0.1MPa, 300K to 0.2MPa . The universal gas constant is 8.314kJ/kg mol K. The work of compression of the gas (in kJ/ kg) is (a) 29.7 (b) 19.9 (c) 13.3 (d) 0 17) A mixture of gases expands from 0.03 m to 0.06 m 3  at a constant pressure of 1 MPa and absorbs 84 KJ of heat during the process. The change in internal energy of the mixture is (a) 30 KJ (b) 54 KJ (c) 84 KJ (d) 114 KJ 18) In a cyclic heat engine operating between the temperatures limit of 600 0 C and 20 0 C. The least rate of heat rejection per KW net output of the engine is (a) 0.46 KW (b) 0.505 KW (c) 0.588 KW (d) 0.65 KW 19) The COP of Carnot refrigeration cycle decreases on (a) Decreasing the difference in operating temperatures (b) Keeping the upper temperature constant and increasing the lower temperature (c) Increasing the upper temperature and keeping the lower temperature constant. (d) Increasing the upper temperature and decreasing the lower temperature   20) The loss of available energy associate with the transfer of 1000 KJ of heat from a constant temperature system at 600 K to another at 400 K when the environmental temperature 300 K is (a) 166.67 KJ (b) 250 KJ (c) 500 KJ (d) 750 KJ  󰁓󰀮󰁋󰀮󰁅󰁮󰁧󰁩󰁮󰁥󰁥󰁲󰁩󰁮󰁧 󰁁󰁣󰁡󰁤󰁥󰁭󰁹 󲀓 󰁇󰁡󰁴󰁥 󰁍󰁯󰁤󰁥󰁬 󰁔󰁥󰁳󰁴 󰀱 󰀨 󰁍󰁥󰁣󰁨 󲀓 󰁔󰁨󰁥󰁲󰁭󰁯󰁤󰁹󰁮󰁡󰁭󰁩󰁣󰁳󰀩   󰁐󰁲󰁥󰁰󰁡󰁲󰁥󰁤 󰁢󰁹 󰁓󰁒󰁉󰁎󰁉󰁖󰁁󰁓󰁁󰁎󰀮󰁖 󰁐󰁡󰁧󰁥 󰀳 21) COP of the heat pump used for heating a room at 20 0 C by exchanging heat with river water at 10 0 C is (a) 0.5 (b) 2 (c) 28.3 (d) 29.3 22) At what value of temperature does the Celsius and Fahrenheit scale shows the same value (a) – 40 (b) 40 (c) 30 (d) – 30 23) If an engine of 40 % efficiency drives a refrigerator having COP of 5, then the heat input to the engine for each KJ of heat removed from the cold body of the refrigerator is (a) 0.5 KJ (b) 0.75 KJ (c) 1.00 KJ (d) 1.25 KJ 24) In an adiabatic process, 5000 J of work is  performed on a system. The system returns to its srcinal state while 1000 J of heat is added. The work done during the non adiabatic process is (a) + 4000 J (b) – 4000 J (c) + 6000 J (d) – 6000 J 25) When air is compressed, the enthalpy is increased from 100 to 200 KJ/kg. Heat lost during this compression is 50 KJ/kg. Neglecting kinetic and potential energies, the power required for a mass flow of 2 Kg/s of air through the compressor will be (a) 300 KW (b) 200 KW (c) 100 KW (d) 50 KW 26) For a reversible power cycle, the operating temperature limits are 800 K and 300 K. It takes 400 KJ of heat. The unavailable work will be (a) 250 KJ (b) 150 KJ (c) 120 KJ (d) 100 KJ 27) Air enters an adiabatic nozzle at 300KPa ,500K with a velocity of 10 m/s. It leaves the nozzle at 100 KPa with a velocity of 180 m/s. The inlet area is 80 cm 2 . The specific heat of air is 1008J/kgk. The exit temperature of the air is a) 516 K  b) 523 K c) 484 K d) 468 K 28) According to Charle's Law (a) At constant pressure the volume of a gas is  proportional to its temperature (b) At constant pressure the volume of a gas is  proportional to its absolute temperature (c) At constant gauge pressure the molecular volume of a gas is proportional to its absolute temperature (d) At constant volume the absolute pressure is  proportional to its absolute temperature 29) Internal energy of a perfect gas depends on (a) Temperature, specific heats and pressure (b) Temperature, specific heats and enthalpy (c) Temperature, specific heats and entropy (d) Temperature only 30) During throttling process (a) Internal energy does not change (b) Pressure does not change, (c) Entropy does not change (d) Enthalpy does not change (e) Volume changes in negligible.

Jul 23, 2017

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Jul 23, 2017
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