Main 13 · Advanced 21
First law and internal energy
- Advanced 2026PhysicsMultiple correct
Ten moles of an ideal monoatomic gas, initially in state at atmospheric pressure and temperature C, is enclosed in a metal cylinder of volume fitted with a frictionless piston. The gas is suddenly compressed to state with volume . Now, keeping the piston stationary, the cylinder is submerged in a water bath of temperature C until the gas reaches the temperature of the water bath, which is denoted as state . Finally, while still in the water bath, the piston is brought slowly to its initial position, which is denoted as state . If is universal gas constant, then the correct option(s) is/are:
[Given: ] - Main 2026PhysicsInteger
5 moles of unknown gas is heated at constant volume from 10 °C to 20 °C. The molar specific heat of this gas at constant pressure cal/mol.°C and J/mol.°C. The change in the internal energy of the gas is ________ calorie.
- Main 2026PhysicsSingle correct
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Statement I: Change in internal energy of a system containing mole of ideal gas can be written as , where , = initial temperature, = final temperature.
Statement II: Relation between degree of freedom and is
Choose the correct answer from the options given below
- Main 2026PhysicsSingle correct
Consider the following statements:
A. Zeroth law of thermodynamics gives concept of temperature
B. First law of thermodynamics gives concept of internal energy
C. In isothermal expansion of ideal gas,
D. Product of intensive and extensive variables is extensive
E. The ratio of any extensive variable to mass will be an extensive variable
Choose the correct combination of statements from the options given below:
- Main 2026PhysicsSingle correct
One mole of diatomic gas having rotational modes only is kept in a cylinder with a piston system. The cross-section area of the cylinder is 4 cm². The gas is heated slowly to raise the temperature by 1.2 °C during which the piston moves by 25 mm. The amount of heat supplied to the gas is ________ J.
(Atmospheric pressure = 100 kPa, R = 8.3 J/mol. K) (Neglect mass of the piston)
- Advanced 2024PhysicsList match
One mole of a monatomic ideal gas undergoes the cyclic process J→K→L→M→J, as shown in the P-T diagram.
Match the quantities mentioned in List-I with their values in List-II and choose the correct option.
[ is the gas constant.]
- Advanced 2023PhysicsInteger
A closed container contains a homogeneous mixture of two moles of an ideal monatomic gas () and one mole of an ideal diatomic gas (). Here, is the ratio of the specific heats at constant pressure and constant volume of an ideal gas. The gas mixture does a work of 66 Joule when heated at constant pressure. The change in its internal energy is _____ Joule.
- Advanced 2022PhysicsList match
List I describes thermodynamic processes in four different systems. List II gives the magnitudes (either exactly or as a close approximation) of possible changes in the internal energy of the system due to the process.
Which one of the following options is correct?
- Main 2022PhysicsInteger
A monoatomic gas performs a work of where Q is the heat supplied to it. The molar heat capacity of the gas will be ______ R during this transformation.
Where R is the gas constant.
- Main 2022PhysicsSingle correct
A thermally insulated vessel contains an ideal gas of molecular mass M and ratio of specific heats 1.4. Vessel is moving with speed and is suddenly brought to rest. Assuming no heat is lost to the surrounding and vessel temperature of the gas increases by :
(R = universal gas constant)
- Main 2022PhysicsSingle correct
A sample of an ideal gas is taken through the cyclic process ABCA as shown in figure. It absorbs, 40 J of heat during the part AB, no heat during BC and rejects 60 J of heat during CA. A work of 50 J is done on the gas during the part BC. The internal energy of the gas at A is 1560 J. The workdone by the gas during the part CA is :
- Main 2022PhysicsSingle correct
7 mol of a certain monoatomic ideal gas undergoes a temperature increase of 40K at constant pressure. The increase in the internal energy of the gas in this process is :
(Given R = 8.3 JK mol)
- Main 2022PhysicsInteger
At a certain temperature, the degrees of freedom per molecule for gas is 8. The gas performs 150 J of work when it expands under constant pressure. The amount of heat absorbed by the gas will be ______ J.
- Advanced 2021PhysicsSingle correct
An ideal gas undergoes a four step cycle as shown in the diagram below. During this cycle, heat is absorbed by the gas in
- Advanced 2021PhysicsSingle correct
The value of is
- Advanced 2021PhysicsSingle correct
The value of is
- Advanced 2020PhysicsInteger
A thermally isolated cylindrical closed vessel of height 8 m is kept vertically. It is divided into two equal parts by a diathermic (perfect thermal conductor) frictionless partition of mass 8.3 kg. Thus the partition is held initially at a distance of 4 m from the top, as shown in the schematic figure below. Each of the two parts of the vessel contains 0.1 mole of an ideal gas at temperature 300 K. The partition is now released and moves without any gas leaking from one part of the vessel to the other. When equilibrium is reached, the distance of the partition from the top (in m) will be ______ (take the acceleration due to gravity and the universal gas constant ).
- Advanced 2019PhysicsList match
If the process carried out on one mole of monatomic ideal gas is as shown in figure in the -diagram with , the correct match is,
- Advanced 2019PhysicsList match
If the process on one mole of monatomic ideal gas is as shown in the -diagram with , the correct match is,
- Advanced 2018PhysicsMultiple correct
One mole of a monatomic ideal gas undergoes a cyclic process as shown in the figure (where is the volume and is the temperature). Which of the statements below is (are) true?