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NEET Thermodynamics PYQs with Solutions

297 previous year questions from Thermodynamics (NEET UG Physics) with answers and solutions. Numbered list, year tags, and one-tap solutions — built for serious JEE / NEET practice.

297 questionsPhysics2002–2026Answers + solutions

About Thermodynamics PYQs

Thermodynamics has 297 previous year questions in the Quantrex Academy NEET UG Physics bank. The 220 questions in this list come from NEET (170), JIPMER (27) and MHT CET Medical (23), spanning 2002 to 2026. Each question opens on its own page with the options, the correct answer and the worked solution where available.

Questions by year (this list)

  • 2026: 26
  • 2025: 2
  • 2024: 2
  • 2023: 3
  • 2022: 2
  • 2020: 3
  • 2019: 1
  • 2018: 7
  • 2017: 5
  • 2016: 7
  • 2015: 9
  • 2014: 3

Thermodynamics questions with solutions

1

The work done by an ideal gas during closed cycle 1arrow 2 arrow 3 arrow 4 arrow 1 as shown in figure is

MHT CET Medical 2026 Solution View → 2

Which of the following statements is NOT CORRECT? In an isothermal process, a. there is perfect thermal equilibrium with environment. b. there is no change in internal energy

MHT CET Medical 2026 Solution View → 3

Let η_1 be the efficiency of a Carnot engine at T_H = 547^ ^ ∘ C and T_C = 247^ ^ ∘ C while η_2 is the efficiency at T_H = 847^ ^ ∘ C and T_C = 147^ ^ ∘ C . If η_1 = (x)/(41)η_2

MHT CET Medical 2026 Solution View → 4

Identify the INCORRECT statement for isobaric process.

MHT CET Medical 2026 Solution View → 5

A gas for which γ = 5 / 3 \ (γ = C_p / C_v ) is heated at constant pressure. The percentage of heat supplied used for external work is

MHT CET Medical 2026 Solution View → 6

A mono-atomic ideal gas, initially at temperature T_1 is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature T_2

MHT CET Medical 2026 Solution View → 7

A gas for which γ is 3/2 is heated at constant pressure. The percentage of heat supplied for external work is nearly

MHT CET Medical 2026 Solution View → 8

One mole of an ideal gas in initial state A undergoes a cyclic process ABCA, as shown in the figure. Its pressure at A is P_0 . Choose the correct option from the following.

MHT CET Medical 2026 Solution View → 9

An ideal mono-atomic gas is heated at constant pressure. The fraction of the total energy applied which increases the internal energy for the gas is

MHT CET Medical 2026 Solution View → 10

Carnot engine has an efficiency of (1)/(7) . When the temperature of the sink is reduced by 60 K, its efficiency is doubled. The temperature of the source is

MHT CET Medical 2026 Solution View → 11

The second law of thermodynamics deals with the transfer of a. only work. b. momentum. c. heat. d. only pressure.

MHT CET Medical 2026 Solution View → 12

For an isochoric process, which of the following statements is NOT true?

MHT CET Medical 2026 Solution View → 13

For the Carnot heat engine, if the temperature of the hot reservoir is increased, then efficiency of the Carnot engine

MHT CET Medical 2026 Solution View → 14

If R is the universal gas constant then the amount of heat needed to raise the temperature of 3 moles of an ideal monoatomic gas from 273 K to 393 K when no work is done is

MHT CET Medical 2026 Solution View → 15

The relation obeyed by a perfect gas during an adiabatic process is pV^ 3/2 . The initial temperature of the gas is 'T'. When the gas is compressed to half of its initial volume

MHT CET Medical 2026 Solution View → 16

Thermodynamic change in the system from state (P_1, V_1) to (P_2, V_2) is shown in the figure. The work done by the system is

MHT CET Medical 2026 Solution View → 17

A monoatomic gas is compressed to (1/8) th of its volume adiabatically. If its initial pressure is P_0 , then increase in the pressure will be

MHT CET Medical 2026 Solution View → 18

For a cyclic thermodynamic process

MHT CET Medical 2026 Solution View → 19

For an adiabatic process, choose the correct relation

MHT CET Medical 2026 Solution View → 20

In thermodynamic processes, which one of the following statements is 'NOT' correct ?

MHT CET Medical 2026 Solution View → 21

A gas is taken through a cycle A arrow B arrow C arrow A , as shown in the figure. The net work done by the gas is

MHT CET Medical 2026 Solution View → 22

A rigid diatomic ideal gas is compressed adiabatically to (1/32) of its initial volume. If the initial temperature of the gas is T_1 (in kelvin) and the final temperature is "

MHT CET Medical 2026 Solution View → 23

Which of the following is NOT a correct equation for adiabatic process?

MHT CET Medical 2026 Solution View → 24

One mole of an ideal monatomic gas undergoes a cyclic process as shown in the figure. The total heat supplied to the gas is :

NEET 2026 Solution View → 25

An electric heater supplies heat to a system at a rate of 100 W. If the system performs work at a rate of 75 J/s, then the rate at which internal energy increases will be :

NEET 2026 Solution View → 26

In an adiabatic expansion, the temperature of one mole of an ideal monatomic gas ( γ=5/3 ) decreases from 60 K to 50 K. The work done by the gas in the process is : (Take the

NEET 2026 Solution View → 27

A container has two chambers of volumes V_1=2 litres and V_2=3 litres separated by a partition made of a thermal insulator. The chambers contains n_1=5 and n_2=4 moles of ideal

NEET 2025 Solution View → 28

Two gases A and B are filled at the same pressure in separate cylinders with movable pistons of radius r_A and r_B , respectively. On supplying an equal amount of heat to both the

NEET 2025 Solution View → 29

The equilibrium state of a thermodynamic system is described by A. Pressure B. Total heat C. Temperature D. Volume E. Work done

NEET 2024 Solution View → 30

A thermodynamic system is taken through the cycle a b c d a . The work done by the gas along the path b c is:

NEET 2024 Solution View → 31

A Carnot engine has an efficiency of 50 % when its source is at a temperature 327 ° C . The temperature of the sink is:

NEET 2023 Solution View → 32

A container of volume 200 ~cm^3 contains 0.2 mole of hydrogen gas and 0.3 mole of argon gas. The pressure of the system at temperature 200 ~K(R=8.3 ~J ~K^ -1 ~mol^ -1 ) will be

NEET 2023 Solution View → 33

For the given cycle, the work done during isobaric process is:

NEET 2023 Solution View → 34

An ideal gas follows a process described by the equation PV^2=C from the initial (P_1, ~V_1, ~T_1) to final ( .P_2, ~V_2, ~T_2) thermodynamic states, where C is a constant. Then:

NEET 2022 Solution View → 35

An ideal gas undergoes four different processes from the same initial state as shown in the figure below. Those processes are adiabatic, isothermal, isobaric and isochoric. The

NEET 2022 Solution View → 36

The efficiency of a Carnot engine depends upon

NEET 2020 Solution View → 37

The P - V diagram for an ideal gas in a piston cylinder assembly undergoing a thermodynamic process is shown in the figure. The process is

NEET 2020 Solution View → 38

Two cylinders A and B of equal capacity are connected to each other via a stop cock. A contains an ideal gas at standard temperature and pressure. B is completely evacuated. The

NEET 2020 Solution View → 39

In which of the following processes, heat is neither absorbed nor released by a system?

NEET 2019 Solution View → 40

If the efficiency of an engine is 50 \% and its work output is 500 J , then find input.

JIPMER 2018 Solution View → 41

The efficiency of a heat engine is 1 / 6 . Its efficiency double when the temperature of sink decrease by 62^ ∘ C , its efficiency doubles. Then, what is the temperature of source?

JIPMER 2018 Solution View → 42

A Carnot engine absorbs 6 × 10^5 cal at 227^ ∘ C . The work done per cycle by the engine, if its sink is maintained at 127^ ∘ C is

JIPMER 2018 Solution View → 43

If a machine perform 4000 J output work and 1000 J is inside loss due to friction, then the find efficiency?

JIPMER 2018 Solution View → 44

The efficiency of an ideal gas with adiabatic exponent γ for the shown cyclic process would be

JIPMER 2018 Solution View → 45

The Volume (V) of a monoatomic gas varies with its temperature (T) , as shown in the graph. The ratio of work done by the gas, to the heat absorbed by it, when it undergoes a

NEET 2018 Solution View → 46

The efficiency of an ideal heat engine working between the freezing point and boiling point of water, is

NEET 2018 Solution View → 47

p-V plots for two gases during adiabatic process as shown in figure plots 1 and 2 should correspond respectively to

JIPMER 2017 Solution View → 48

The temperature of source and sink of a heat engine are 127^ ∘ C and 27^ ∘ C , respectively. An inventor claims its efficiency to be 26 \% , then

JIPMER 2017 Solution View → 49

Thermodynamic processes are indicated in the following diagram. Match the following Column – 1 Column - 2 P. Process I a. Adiabatic Q. Process II b. Isobaric R. Process III

NEET 2017 Solution View → 50

A gas mixture consists of 2 moles of O _ 2 and 4 moles of Ar at temperature T . Neglecting all vibrational modes, the total internal energy of the system is ( R is universal gas

NEET 2017 Solution View → 51

A Carnot's engine having an efficiency of (1)/(10) as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the

NEET 2017 Solution View → 52

The slope of isothermal and adiabatic curves are related as

JIPMER 2016 Solution View → 53

The volume of an ideal gas is doubled in an isothermal process. Then, which of the following is true?

JIPMER 2016 Solution View → 54

One mole of an ideal monatomic gas undergoes a process described by the equation P V ^ 3 = constant. The heat capacity of the gas during this process is

NEET 2016 Solution View → 55

The temperature inside a refrigerator is t _ 2 ^ o C and the room temperature is t _ 1 ^ o C . The amount of heat delivered to the room for each joule of electrical energy

NEET 2016 Solution View → 56

A given sample of an ideal gas occupies a volume, V at a pressure, P and absolute temperature,~ T . The mass of each molecule of the gas is m . Which of the following gives the

NEET 2016 Solution View → 57

A refrigerator works between 4 ^ o C and 30 ^ o C . It is required to remove 600 calories of heat every second in order to keep the temperature of the refrigerated space constant.

NEET 2016 Solution View → 58

A gas is compressed isothermally to half its initial volume. The same gas is compressed separately through an adiabatic process until its volume is again reduced to half. Then:

NEET 2016 Solution View → 59

A diatomic gas (γ=1.4) does 200 J of work when it is expanded isobarically. Find the heat given to the gas in the process.

JIPMER 2015 Solution View → 60

The given p-V diagram shows gases during adiabatic process. Plots 1 and 2 should correspond respectively to

JIPMER 2015 Solution View → 61

1 kg of water is converted into steam at the same temperature and at 1 atm ( 100 kPa ). The density of water and steam are 1000 kgm^ -3 and 0.6 kgm^ -3 respectively. The latent

JIPMER 2015 Solution View → 62

For an adiabatic expansion of a mono atomic perfect gas, the volume increases by 24 \% . What is the percentage decrease in pressure?

JIPMER 2015 Solution View → 63

An ideal gas is compressed to half of its initial volume by means of several processes. Which of the process results in the maximum work done on the gas?

NEET 2015 Solution View → 64

The coefficient of performance of a refrigerator is 5 . If the temperature inside the freezer is - 20 ° C , the temperature of the surrounding to which it rejects heat is:

NEET 2015 Solution View → 65

A Carnot engine, having an efficiency of η = (1)/(10) as heat engine, is used as a refrigerator. If the work done on the system is 10J , the amount of energy absorbed from the

NEET 2015 Solution View → 66

Figure below shows two paths that may be taken by a gas to go from a state A to a state C. In process AB, 400 J of heat is added to the system and in process BC, 100 J of heat is

NEET 2015 Solution View → 67

One mole of an ideal diatomic gas undergoes a transition from A to B along a path AB as shown in the figure, The change in internal energy of the gas during the transition is:

NEET 2015 Solution View → 68

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of absolute temperature. The ratio (C_p)/(C_V) for the gas is

JIPMER 2014 Solution View → 69

A monoatomic gas at a pressure P, having a volume V expands isothermally to a volume 2V and then adiabatically to a volume 16V . The final pressure of the gas is: (take γ = 5 / 3 )

NEET 2014 Solution View → 70

A thermodynamics system undergoes cyclic process ABCDA as shown in Figure. The work done by the system in the cycle is:

NEET 2014 Solution View → 71

A system is taken from state a to state c by two paths a d c and a b c as shown in the figure. The internal energy a is U_2=10 J. Along the path adc the amount of heat heat

NEET 2013 Solution View → 72

Two Carnot engines A and B are operated in series. The engine A receives heat from the source at temperature T_1 and rejects the heat to the sink at temperature T . The second

NEET 2013 Solution View → 73

Which of the following relations does not give the equation of an adiabatic process, where terms have their usual meaning?

NEET 2013 Solution View → 74

In the given ( V-T) diagram, what is the relation between pressures p_1 and p_2 ?

NEET 2013 Solution View → 75

A gas is taken through the cycle A arrow B arrow C arrow A , as shown. What is the net work done by the gas?

NEET 2013 Solution View → 76

A thermodynamic system is taken through the cycle A B C D as shown in figure. Heat rejected by the gas during the cycle is

NEET 2012 Solution View → 77

One mole of an ideal gas goes from an initial state A to final state B via two processes. It first undergoes isothermal expansion from volume V to 3 V and then its volume is

NEET 2012 Solution View → 78

An ideal gas goes from state A to state B via three different processes as indicated in the p-V diagram If Q_1, Q_2, Q_3 indicate the heat absorbed by the gas along the three

NEET 2012 Solution View → 79

In Carnot engine efficiency is 40 \% at hot reservoir temperature T . For efficiency 50 \% , what will be temperature of hot reservoir?

JIPMER 2011 Solution View → 80

When 1 ~kg of ice at 0^ ∘ C melts to water at 0^ ∘ C , the resulting change in its entropy, taking latent heat of ice to be 80 cal / ^ ∘ C , is

NEET 2011 Solution View → 81

During an isothermal expansion, a confined ideal gas does 150 ~J of work against its surroundings. This implies that

NEET 2011 Solution View → 82

A mass of diatomic gas (γ=1.4) at a pressure of 2 ~atm is compressed adiabatically so that its temperature rise from 27^ ∘ C to 927^ ∘ C . The pressure of the gas is final state is

NEET 2011 Solution View → 83

1 mole of an ideal gas at an initial temperature of T ~K does 6 R joule of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant

JIPMER 2010 Solution View → 84

If Δ U and Δ W represent the increase in internal energy and work done by the system respectively in a thermodynamical process, which of the following is true?

NEET 2010 Solution View → 85

The work of 146 kJ is performed in order to compress one kilo mole of a gas adiabatically and in this process the temperature of the gas increases by 7^ ∘ C . The gas is (R=8.3 ~J

JIPMER 2009 Solution View → 86

Which of the following parameters does not characterise the thermodynamic state of matter?

JIPMER 2009 Solution View → 87

In thermodynamic processes which of the following statements is not true?

NEET 2009 Solution View → 88

In thermodynamic processes which of the following statements is not true?

NEET 2009 Solution View → 89

The internal energy change in a system that has absorbed 2 kcal of heat and done 500 ~J of work is

NEET 2009 Solution View → 90

The internal energy change in a system that has absorbed 2 k cal of heat and done 500 ~J of work is :

NEET 2009 Solution View → 91

We consider a thermodynamic system. If Δ U represents the increase in its internal energy and W the work done by the system, which of the following statements is true?

JIPMER 2008 Solution View → 92

When you make ice cubes, the entropy of water

JIPMER 2008 Solution View → 93

If Q, E and W denote respectively the heat added, change in internal energy and the work done in a closed cycle process, then

NEET 2008 Solution View → 94

If Q, E and W denote respectively the heat added, change in internal energy and the work done in a closed cycle process, then

NEET 2008 Solution View → 95

Which of the following processes is reversible?

JIPMER 2007 Solution View → 96

An ideal gas heat engine operates in Carnot cycle between 227^ ∘ C and 127^ ∘ C . It absorbs 6 × 10^4 cal of heat at higher temperature. Amount of heat converted to work is

JIPMER 2007 Solution View → 97

An engine has an efficiency of 1 / 6 . When the temperature of sink is reduced by 62^ ∘ C , its efficiency is doubled. Temperatures of the source is:

NEET 2007 Solution View → 98

A perfect gas is found to obey the relation P V^ 3 / 2 = constant during an adiabatic process. If such a gas initially at a temperature T , is compressed to half of its initial

JIPMER 2006 Solution View → 99

In isothermal process, which of the following is not true?

JIPMER 2006 Solution View → 100

A Carnot engine whose sink is at 300 ~K has an efficiency of 40 \% . By how much should the temperature of source be increased so as to increase its efficiency by 50 \% of

NEET 2006 Solution View → 101

A monoatomic gas supplied the heat Q very slowly keeping the pressure constant. The work done by the gas will be

JIPMER 2005 Solution View → 102

Which of the following processes is reversible?

NEET 2005 Solution View → 103

An ideal gas heat engine operates in carnot cycle between 227^ ∘ C and 127^ ∘ C . It absorbs 6 × 10^4 cal of heat at higher temperature. Amount of heat converted into work, is:

NEET 2005 Solution View → 104

If the heat of 110 J is added to a gaseous system, whose internal energy is 40 J , then the amount of external work done is

JIPMER 2004 Solution View → 105

Amount of work which can be obtained from 200 cal heat, will be

JIPMER 2004 Solution View → 106

One mole of an ideal gas at an initial temperature of T~ K does 6~ R joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant

NEET 2004 Solution View → 107

An ideal gas heat engine operates in a Carnot cycle between 227^ ∘ C and 127^ ∘ C . It absorbs 6 kcal at the higher temperature. The amount of heat (in kcal) converted into work

NEET 2003 Solution View → 108

The efficiency of the Carnot engine is 50 \% and the temperature of the sink is 500 ~K . If the temperature of the source is kept constant and its efficiency raised to 60 \%

NEET 2002 Solution View → 109

A cyclic process A B C D is shown below in the given P-V diagram. In the following answers the one that represents the same process as in P-V diagram :

NEET Solution View → 110

An ideal gas is subjected to a cyclic process A B C D as depicted in the p-V diagram given below Which of the following curves represents the equivalent cyclic process?

NEET Solution View → 111

3 moles of an ideal monoatomic gas performs A B C D A cyclic process as shown in figure below. The gas temperatures are T_A=400 ~K , T_B=800 ~K, T_C=2400 ~K and T_D=1200 ~K . The

NEET Solution View → 112

Three moles of an ideal monoatomic gas undergoes a cyclic process as shown in the figure. The temperature of the gas in different states marked as 1, 2, 3 and 4 are 400 ~K, 700

NEET Solution View → 113

Pressure (P) versus density (d) graph of an ideal gas is shown in the figure. Choose the correct statement.

NEET Solution View → 114

A graph drawn between absolute temperature and volume of 3 moles of helium gas as shown in the figure. If 5 cal of heat is used in the process, then the work done is

NEET Solution View → 115

An ideal gas is taken through the cycle \(A arrow\) \(B arrow C arrow A\) as shown in the figure. If the net heat supplied to the gas in the cycle is \(5 ~J\). The magnitude of

NEET Solution View → 116

One mole of an ideal diatomic gas undergoes a transition from A to B along a path AB as shown in figure. The change in internal energy of the gas during the transition is

NEET Solution View → 117

Which one of the graphs below best illustrates the relationship between internal energy U of an ideal gas and temperature T of the gas in K ?

NEET Solution View → 118

One mole of an ideal monoatomic gas undergoes the process A arrow B arrow C arrow D arrow A as shown in the graph. The work done during the process is

NEET Solution View → 119

In the given pressure (P) - absolute temperature (T) graph of an ideal gas, the relation between volumes V_1, V_2, V_3 and V_4 is

NEET Solution View → 120

A cyclic process is shown in the p-T diagram. Which of the curves show the same process on a P - V diagram?

NEET Solution View →
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