Question Bank for JEE Main & Advanced Physics Thermodynamical Processes Topic Test - Thermodynamical Processes

1)

A carnots reversible engine converts \[\frac{1}{6}th\] of heat input into work. When the temperature of sink is reduced 62 K, the efficiency of carnotss cycle, becomes \[\frac{1}{3}.\] Calculate temperature of source and sink

A)

372K, 310K

B)

772K, 312K

C)

672K, 610K

D)

None of these

View Solution

2)

A monatomic gas undergoes a process given by \[2dU+3dW=0,\] then the process is

A)

isobaric

B)

adiabatic

C)

isothermal

D)

none of these

View Solution

3)

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

B)

36 kJ, - 36 kJ

C)

46 kJ, - 46 kJ

D)

- 36 kJ, 36 kJ

View Solution

4)

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

B)

\[{{p}^{1/n}}\]

C)

\[\frac{p}{n}\]

D)

\[{{p}^{n}}\]

View Solution

5)

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

B)

25 kJ

C)

15 kJ

D)

20 kJ

View Solution

6)

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)

\[3.46\times {{10}^{4}}J\]

B)

\[2.33\times {{10}^{3}}J\]

C)

\[12\times {{10}^{5}}\]

D)

\[2.33\times {{10}^{4}}J\]

View Solution

7)

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

B)

\[7.5\times {{10}^{5}}\] ergs

C)

\[12\times {{10}^{5}}\] joule

D)

\[6\times {{10}^{5}}\] joule

View Solution

8)

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)

\[\frac{13R}{6}\]

B)

\[\frac{19R}{6}\]

C)

\[\frac{23R}{6}\]

D)

\[\frac{17R}{6}\]

View Solution

9)

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

B)

80 J

C)

120 J

D)

60 J

View Solution

10)

Two carnots 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

B)

750 K

C)

450 K

D)

900 K

View Solution

11)

Choose the correct statement for an isolated system.

A)

\[\Delta U(C\to D)=\] negative

B)

\[\Delta Q(A\to B)=\] positive

C)

\[\Delta U=(A-B-C-D-A)\ne 0\]

D)

\[\Delta Q(D\to A)=0\]

View Solution

12)

An imaginary ideal gas with adiabatic exponent \[\gamma =2\] goes through a cycle as shown in figure. Find efficiency of cycle:

A)

\[\frac{1}{9}\]

B)

\[\frac{1}{8}\]

C)

\[\frac{1}{6}\]

D)

\[\frac{1}{5}\]

View Solution

13)

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)

\[{{T}_{0}}\]

B)

\[3{{T}_{0}}\]

C)

\[6{{T}_{0}}\]

D)

\[2{{T}_{0}}\]

View Solution

14)

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)

\[3nR{{T}_{0}}\]

B)

\[nR{{T}_{0}}\]

C)

\[2nR{{T}_{0}}\]

D)

\[6nR{{T}_{0}}\]

View Solution

15)

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)

\[\frac{Q}{n{{T}_{0}}}\]

B)

\[\frac{Q}{2n{{T}_{0}}}\]

C)

\[\frac{Q}{3n{{T}_{0}}}\]

D)

\[\frac{2Q}{n{{T}_{0}}}\]

View Solution

16)

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

A)

He and \[{{O}_{2}}\]

B)

\[{{O}_{2}}\] and He

C)

He and Ar

D)

\[{{O}_{2}}\] and \[{{N}_{2}}\]

View Solution

17)

From the following V-T diagram as shown in the figure. What is true about pressure?

A)

\[{{p}_{1}}<{{p}_{2}}\]

B)

\[{{p}_{1}}>{{p}_{2}}\]

C)

\[{{p}_{1}}={{p}_{2}}\]

D)

Cannot predict

View Solution

18)

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

B)

1.50

C)

1.67

D)

2.00

View Solution

19)

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

B)

\[\frac{P}{V}=\] constant

C)

\[\frac{{{V}^{2}}}{P}=\] constant

D)

none of these

View Solution

20)

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

B)

3

C)

4

D)

5

View Solution

21)

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

B)

350 J

C)

7000 J

D)

750 J

View Solution

22)

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)

\[320{}^\circ C\]

B)

\[39{}^\circ C\]

C)

325 K

D)

\[325{}^\circ C\]

View Solution

23)

P.T graph of an ideal gas of equal number of moles of different volumes are plotted as shown. Choose the correct answer

A)

\[{{V}_{1}}={{V}_{2}}>{{V}_{3}}={{V}_{4}}\]

B)

\[{{V}_{1}}={{V}_{2}}<{{V}_{3}}={{V}_{4}}\]

C)

\[{{V}_{1}}={{V}_{2}}={{V}_{3}}={{V}_{4}}\]

D)

\[{{V}_{4}}>{{V}_{3}}>{{V}_{2}}>{{V}_{1}}\]

View Solution

24)

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

B)

150 J

C)

350 J

D)

200 J

View Solution

25)

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)

\[{{T}_{f}}=\frac{7}{3}{{T}_{0}}\]

B)

\[{{T}_{f}}=\frac{3}{2}{{T}_{0}}\]

C)

\[{{T}_{f}}=\frac{5}{2}{{T}_{0}}\]

D)

\[{{T}_{f}}=\frac{3}{7}{{T}_{0}}\]

View Solution

26)

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

B)

743 J

C)

660 J

D)

620 J

View Solution

27)

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

B)

30 R

C)

40 R

D)

20 R

View Solution

28)

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%

B)

600 J, 66.67%

C)

400 J, 66.67%

D)

600 J, 100%

View Solution

29)

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

B)

- 6 joules

C)

+4 joules

D)

- 4 joules

View Solution

30)

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

B)

decrease and increase respectively

C)

both increase

D)

both decrease

View Solution

31)

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)

B)

Final temperature in (ii) will be equal to (i)

C)

Total heat given to the gas in (i) case is greater than in (ii)

D)

Total heat given to the gas in (ii) case is greater than in (i)

View Solution

32)

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

B)

decreases

C)

remains constant

D)

nothing can be said

View Solution

33)

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)

\[nRT\text{ }\ln \text{ }2\]

B)

\[-nRT\text{ }\ln \text{ }2\]

C)

\[nRT\]

D)

\[-nRT\]

View Solution

34)

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)

\[nRT\text{ }\ln \text{ }2\]

B)

\[-nRT\text{ }\ln \text{ }2\]

C)

nRT

D)

\[-nRT\]

View Solution

35)

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

B)

heat is ejected by the gas

C)

no work is done by the gas

D)

nothing can be said about work as data is insufficient

View Solution

JEE Main & Advanced Physics Thermodynamical Processes Question Bank

done Topic Test - Thermodynamical Processes Total Questions - 35

Download Complete Course

Topic Test - Thermodynamical Processes Total Questions - 35