JEE Main & Advanced Physics Thermodynamical Processes Sample Paper

done Topic Test - Thermodynamical Processes Total Questions - 35    [Download]

• question_answer1)
  A carnot's reversible engine converts \[\frac{1}{6}th\] of heat input into work. When the temperature of sink is reduced 62 K, the efficiency of carnot's cycle, becomes \[\frac{1}{3}.\] Calculate temperature of source and sink
  A)
  372K, 310K       
  done clear
  B)
  772K, 312K
  done clear
  C)
  672K, 610K
  done clear
  D)
  None of these
  done clear
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• question_answer2)
  A monatomic gas undergoes a process given by \[2dU+3dW=0,\] then the process is
  A)
  isobaric
  done clear
  B)
  adiabatic
  done clear
  C)
  isothermal
  done clear
  D)
  none of these
  done clear
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• question_answer3)
  A diesel engine takes in 5 moles of air at \[20{}^\circ C\] and 1 atm, and compresses it adiabatically to \[\frac{1}{10}\text{th}\] of the original volume. If air is diatomic then work done and change in internal energy is
  A)
  - 46 kJ, 46 kJ
  done clear
  B)
  36 kJ, - 36 kJ
  done clear
  C)
  46 kJ, - 46 kJ
  done clear
  D)
  - 36 kJ, 36 kJ
  done clear
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• question_answer4)
  A gas undergoes a process in which its pressure p and volume V are related as \[V{{p}^{n}}=\] constant the bulk modulus for the gas in the process is
  A)
  np
  done clear
  B)
  \[{{p}^{1/n}}\]
  done clear
  C)
  \[\frac{p}{n}\]
  done clear
  D)
  \[{{p}^{n}}\]  
  done clear
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• question_answer5)
  Three moles of an ideal monoatomic gas perform a cycle shown in figure. The gas temperatures in different states are \[{{T}_{1}}=200K,{{T}_{2}}=400K,{{T}_{3}}=1600K\] and \[{{T}_{4}}=800K.\] The work done by the gas during the cycle is (Take \[R=25/3\text{ }J/mol\text{-}K\])
  A)
  5 kJ
  done clear
  B)
  25 kJ
  done clear
  C)
  15 kJ
  done clear
  D)
  20 kJ
  done clear
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• question_answer6)
  The molar heat capacity of a certain substance varies with temperature according to the given equation, \[C=27.2+(4\times {{10}^{-3}})T.\] The heat necessary to change the temperature of 2 mol. of the substance from 300K to 700K is
  A)
  \[3.46\times {{10}^{4}}J\]
  done clear
  B)
  \[2.33\times {{10}^{3}}J\]
  done clear
  C)
  \[12\times {{10}^{5}}\]
  done clear
  D)
  \[2.33\times {{10}^{4}}J\]
  done clear
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• question_answer7)
  A system changes from the state \[({{P}_{1}},\,\,\,{{V}_{1}})\] to \[({{P}_{2}},\,\,\,{{V}_{2}})\] as shown in the figure below. What is the work done by the system?                      
  A)
  \[7.5\times {{10}^{5}}\] joule
  done clear
  B)
  \[7.5\times {{10}^{5}}\] ergs
  done clear
  C)
  \[12\times {{10}^{5}}\] joule
  done clear
  D)
  \[6\times {{10}^{5}}\] joule
  done clear
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• question_answer8)
  A diatomic ideal gas is heated at constant volume until the pressure is doubled and again heated at constant pressure until volume is doubled. The average molar heat capacity for whole process is:
  A)
  \[\frac{13R}{6}\]
  done clear
  B)
  \[\frac{19R}{6}\]
  done clear
  C)
  \[\frac{23R}{6}\]
  done clear
  D)
  \[\frac{17R}{6}\]
  done clear
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• question_answer9)
  An ideal monoatomic gas is confined in a cylinder, fitted with piston, which is connected to spring as shown in figure. The gas is heated by a-small electric heater until the piston moves out slowly by 0.1 m. Find the work done by the gas. Spring constant = 8000 N/m,-piston area \[=8\times {{10}^{-3}}{{\text{m}}^{2}}\] atmospheric pressure \[={{10}^{5}}Pa\].              
  A)
  40 J
  done clear
  B)
  80 J
  done clear
  C)
  120 J
  done clear
  D)
  60 J
  done clear
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• question_answer10)
  Two carnot’s engines A and B are operated in series. The first one A receives heat at 1200 K and rejects to a reservoir at T and K. The second engine B receives the heat rejected by the first engine and in turn rejects to a heat reservoir at 300 K. Calculate the value of T, when work outputs of the two engines are equal.
  A)
  600 K
  done clear
  B)
  750 K
  done clear
  C)
  450 K
  done clear
  D)
  900 K
  done clear
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• question_answer11)
  Choose the correct statement for an isolated system.
  A)
  \[\Delta U(C\to D)=\] negative                        
  done clear
  B)
  \[\Delta Q(A\to B)=\] positive
  done clear
  C)
  \[\Delta U=(A-B-C-D-A)\ne 0\]                   
  done clear
  D)
  \[\Delta Q(D\to A)=0\]
  done clear
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• question_answer12)
  An imaginary ideal gas with adiabatic exponent \[\gamma =2\] goes through a cycle as shown in figure. Find efficiency of cycle:            
  A)
  \[\frac{1}{9}\]
  done clear
  B)
  \[\frac{1}{8}\]
  done clear
  C)
  \[\frac{1}{6}\]
  done clear
  D)
  \[\frac{1}{5}\]
  done clear
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• question_answer13)

  DIRECTION: Read the passage given below and answer the questions that follows:

  In the figure n mole of a monoatomic ideal gas undergo the process ABC as shown in the P-V diagram. The process AB is isothermal and BC is isochoric. The temperature of the gas at A is \[{{T}_{0}}\]. Total heat given to the gas during the process ABC is measured to be Q.

  Temperature of the gas at C is equal to

  A)
  \[{{T}_{0}}\]
  done clear
  B)
  \[3{{T}_{0}}\]
  done clear
  C)
  \[6{{T}_{0}}\]
  done clear
  D)
  \[2{{T}_{0}}\]
  done clear
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• question_answer14)

  DIRECTION: Read the passage given below and answer the questions that follows:

  In the figure n mole of a monoatomic ideal gas undergo the process ABC as shown in the P-V diagram. The process AB is isothermal and BC is isochoric. The temperature of the gas at A is \[{{T}_{0}}\]. Total heat given to the gas during the process ABC is measured to be Q.

  Heat absorbed by the gas in the process BC

  A)
  \[3nR{{T}_{0}}\]
  done clear
  B)
  \[nR{{T}_{0}}\]
  done clear
  C)
  \[2nR{{T}_{0}}\]
  done clear
  D)
  \[6nR{{T}_{0}}\]
  done clear
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• question_answer15)

  DIRECTION: Read the passage given below and answer the questions that follows:

  In the figure n mole of a monoatomic ideal gas undergo the process ABC as shown in the P-V diagram. The process AB is isothermal and BC is isochoric. The temperature of the gas at A is \[{{T}_{0}}\]. Total heat given to the gas during the process ABC is measured to be Q.

  The average molar heat capacity of the gas in process ABC

  A)
  \[\frac{Q}{n{{T}_{0}}}\]
  done clear
  B)
  \[\frac{Q}{2n{{T}_{0}}}\]
  done clear
  C)
  \[\frac{Q}{3n{{T}_{0}}}\]
  done clear
  D)
  \[\frac{2Q}{n{{T}_{0}}}\]
  done clear
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• question_answer16)
   

  P-V plots for two gases during adiabatic process are shown in figure. Plots 1 and 2 should correspond, respectively, to

   
  A)
  He and \[{{O}_{2}}\]
  done clear
  B)
  \[{{O}_{2}}\] and He
  done clear
  C)
  He and Ar
  done clear
  D)
  \[{{O}_{2}}\] and \[{{N}_{2}}\]
  done clear
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• question_answer17)
  From the following V-T diagram as shown in the figure. What is true about pressure? 
  A)
  \[{{p}_{1}}<{{p}_{2}}\]
  done clear
  B)
  \[{{p}_{1}}>{{p}_{2}}\]
  done clear
  C)
   \[{{p}_{1}}={{p}_{2}}\]
  done clear
  D)
  Cannot predict
  done clear
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• question_answer18)
  A gas expands adiabatically at constant pressure such that its temperature \[T\,\propto \,a/\sqrt{V}.\] The value of \[\gamma =({{C}_{p}}/{{C}_{V}})\] of the gas is
  A)
  1.30     
  done clear
  B)
  1.50
  done clear
  C)
  1.67
  done clear
  D)
  2.00
  done clear
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• question_answer19)
  For a certain process the molar heat capacity of an ideal gas is found to be \[\left( {{C}_{v}}+\frac{R}{2} \right).\] For the given process it can be concluded that
  A)
  PV = constant
  done clear
  B)
  \[\frac{P}{V}=\] constant
  done clear
  C)
  \[\frac{{{V}^{2}}}{P}=\] constant
  done clear
  D)
  none of these
  done clear
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• question_answer20)
  2 moles of a mono-atomic gas undergo isobaric expansion as shown in figure. The efficiency for the process is found to be \[\frac{x}{10}\]. Find the value of\[x\].
  A)
  2
  done clear
  B)
  3
  done clear
  C)
  4
  done clear
  D)
  5
  done clear
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• question_answer21)
  A 100 kg piston encloses 32 g of oxygen gas at a temperature of \[{{27}^{o}}C\] in a vertical cylinder of base area of \[4\text{ }d{{m}^{2}}\]. The air pressure outside is \[1\times {{10}^{5}}Pa\]. The axis of the cylinder is vertical, and the piston can move in it without friction. How much heat is to be transferred to the gas to raise the piston by 20 cm. Use \[R=\frac{25}{3}J/mol/K\]
  A)
  3500 J
  done clear
  B)
  350 J
  done clear
  C)
  7000 J
  done clear
  D)
  750 J
  done clear
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• question_answer22)
  An ideal refrigerator has a freezer at a temperature of \[-13{}^\circ C\]. The coefficient of performance of the engine is 5. The temperature of the air (to which heat is rejected) is.
  A)
  \[320{}^\circ C\]
  done clear
  B)
  \[39{}^\circ C\]
  done clear
  C)
  325 K
  done clear
  D)
  \[325{}^\circ C\]
  done clear
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• question_answer23)
  P.T graph of an ideal gas of equal number of moles of different volumes are plotted as shown. Choose the correct answer  
  A)
  \[{{V}_{1}}={{V}_{2}}>{{V}_{3}}={{V}_{4}}\]
  done clear
  B)
  \[{{V}_{1}}={{V}_{2}}<{{V}_{3}}={{V}_{4}}\]
  done clear
  C)
  \[{{V}_{1}}={{V}_{2}}={{V}_{3}}={{V}_{4}}\]
  done clear
  D)
  \[{{V}_{4}}>{{V}_{3}}>{{V}_{2}}>{{V}_{1}}\]
  done clear
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• question_answer24)
  The degrees of freedom per molecule of an ideal gas is 5. Work done by the gas is 100 J when it expands isobarically. The heat absorbed by the gas will be
  A)
  250 J
  done clear
  B)
  150 J
  done clear
  C)
  350 J
  done clear
  D)
  200 J
  done clear
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• question_answer25)
  Two rigid boxes containing different ideal gases are placed on a table. Box A contains one mole of nitrogen at temperature \[{{T}_{0}},\] While Box B contains one mole of helium at temperature (7/3) \[{{T}_{0}}\]. The boxes are then put into thermal contact with each other and heat flows between them until the gases reach a common final temperature (Ignore the heat capacity of boxes). Then, the final temperature of the gases, \[{{T}_{f}},\] in term of \[{{T}_{0}}\] is
  A)
  \[{{T}_{f}}=\frac{7}{3}{{T}_{0}}\]
  done clear
  B)
  \[{{T}_{f}}=\frac{3}{2}{{T}_{0}}\]
  done clear
  C)
  \[{{T}_{f}}=\frac{5}{2}{{T}_{0}}\]
  done clear
  D)
  \[{{T}_{f}}=\frac{3}{7}{{T}_{0}}\]
  done clear
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• question_answer26)
  743 J of heat energy is added to raise the temperature of 5 mole of an ideal gas by 2 K at constant pressure. How much heat energy is required to raise the temperature of the same mass of the gas by 2 K at constant volume?
  A)
  826 J
  done clear
  B)
  743 J
  done clear
  C)
  660 J
  done clear
  D)
   620 J
  done clear
  View Answer play_arrow

• question_answer27)
  A gas expands with temperature according to the relation \[V=k{{T}^{2/3}}\]. Calculate work done when the temperature changes by 60 K?
  A)
  10 R    
  done clear
  B)
  30 R
  done clear
  C)
  40 R    
  done clear
  D)
  20 R
  done clear
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• question_answer28)
  For a cyclic process \[A\to B\to C\to A,\] the following information is given

  Path	\[\Delta Q\](Heat supplied)	\[\Delta U\] (Increase in internal energy)	Work done by system on surrounding
  \[A\to B\]	600 J	200 J	400 J
  \[B\to C\]	- 100 J	100 J	- 200 J
  \[C\to A\]	- 100 J	- 300 J	200 J

  Calculate the heat of the cycle and efficiency of cycle.
  A)
  400 J, 100%
  done clear
  B)
  600 J, 66.67%
  done clear
  C)
  400 J, 66.67%
  done clear
  D)
  600 J, 100%
  done clear
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• question_answer29)

  A certain mass of gas is taken from an initial thermodynamic state A to another state B by process I and II. In process I the gas does 5 joules of work and absorbs 4 joules of heat energy. In process II, the gas absorbs 5 joules of heat. The work done by the gas in process II (see figure) is

  A)
  +6 joules
  done clear
  B)
  - 6 joules
  done clear
  C)
  +4 joules
  done clear
  D)
  - 4 joules
  done clear
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• question_answer30)
  Two vessels A and B contain water at temperature \[{{T}_{A}}\] and \[{{T}_{B}},\] at \[10{}^\circ C\] and \[2{}^\circ C\] respectively. If the water in both the vessels were compressed adiabatically and if we take into account the finite bulk modulus of  elasticity of water, then \[{{T}_{A}}\] and \[{{T}_{B}}\]
  A)
  increase and decrease respectively
  done clear
  B)
  decrease and increase respectively
  done clear
  C)
  both increase     
  done clear
  D)
  both decrease
  done clear
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• question_answer31)

  An ideal gas can be expanded from an initial state to a certain volume through two different processes

  (i) \[P{{V}^{2}}=\] constant and

  (ii) \[P=K{{V}^{2}}\] where K is a positive constant. Then

  A)
  Final temperature in (i) will be greater then in (ii)
  done clear
  B)
  Final temperature in (ii) will be equal to (i)
  done clear
  C)
  Total heat given to the gas in (i) case is greater than in (ii)
  done clear
  D)
  Total heat given to the gas in (ii) case is greater than in (i)
  done clear
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• question_answer32)

  Direction: An ideal diatomic gas is confined in a cylinder A of volume \[{{V}_{0}},\] this cylinder is connected to another cylinder B with the help of tube of a negligible volume. The cylinder B is fitted with a movable piston which can be adjusted from outside. Initially, the piston is adjusted so that volume of B is the same as volume of A i.e., \[{{V}_{0}}\]. B is evacuated and the stopcork is opened so that gas expands and occupies the volume \[2{{V}_{0}}\]. [System is thermally isolated from the surroundings].

  During this free expansion, the internal energy of the system. Now with the stop-cork open, the piston is slowly moved to compress the gas back to cylinder A at temperature T. For this

  A)
  increases
  done clear
  B)
  decreases
  done clear
  C)
  remains constant
  done clear
  D)
  nothing can be said
  done clear
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• question_answer33)

  Direction: An ideal diatomic gas is confined in a cylinder A of volume \[{{V}_{0}},\] this cylinder is connected to another cylinder B with the help of tube of a negligible volume. The cylinder B is fitted with a movable piston which can be adjusted from outside. Initially, the piston is adjusted so that volume of B is the same as volume of A i.e., \[{{V}_{0}}\]. B is evacuated and the stopcork is opened so that gas expands and occupies the volume \[2{{V}_{0}}\]. [System is thermally isolated from the surroundings].

  Work done on the gas is [for n moles of gas]

  A)
  \[nRT\text{ }\ln \text{ }2\]
  done clear
  B)
  \[-nRT\text{ }\ln \text{ }2\]
  done clear
  C)
  \[nRT\]
  done clear
  D)
  \[-nRT\]
  done clear
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• question_answer34)

  Direction: An ideal diatomic gas is confined in a cylinder A of volume \[{{V}_{0}},\] this cylinder is connected to another cylinder B with the help of tube of a negligible volume. The cylinder B is fitted with a movable piston which can be adjusted from outside. Initially, the piston is adjusted so that volume of B is the same as volume of A i.e., \[{{V}_{0}}\]. B is evacuated and the stopcork is opened so that gas expands and occupies the volume \[2{{V}_{0}}\]. [System is thermally isolated from the surroundings].

  The heat absorbed by the gas is

  A)
  \[nRT\text{ }\ln \text{ }2\]
  done clear
  B)
  \[-nRT\text{ }\ln \text{ }2\]
  done clear
  C)
  nRT     
  done clear
  D)
  \[-nRT\]
  done clear
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• question_answer35)
  In a cyclic process, a gas is taken from state A to B via path-I as shown in the indicator diagram and taken back to state A from state B via path-II. In the complete cycle:            
  A)
  work is done by the gas
  done clear
  B)
  heat is ejected by the gas
  done clear
  C)
  no work is done by the gas
  done clear
  D)
  nothing can be said about work as data is insufficient
  done clear
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