Thermodynamics practice · Medium

Two identical cylinders $A$ and $B$ with frictionless pistons contain the same ideal gas at the same temperature and the same volume $V$. The mass of gas $A$ is $m_A$ and that of $B$ is $m_{B}$. The gas in each cylinder is now allowed to expand isothermally to the same final volume $2 {V}$. The change in the pressure in ${A}$ and $B$ are found to be $\Delta P$ and $2 \Delta P$ respectively. Then,

An ideal gas is made to go through a cyclic thermodynamical process in four steps. The amount of heat involved are ${Q_1} = 600J,{Q_2} = - 400J,{Q_3} = - 300J$ and ${Q_4}$=200 J respectively. The corresponding work involved are ${W_1} = 300J,{W_2} = - 200J,{W_3} = - 150J$ and ${W_4}$. What is the value of ${W_4}$

One mole of an ideal monatomic gas at temperature $T_0$ expands slowly according to the law $P / V=$ constant. If the final temperature is $3 T_0$, heat supplied to the gas is:

${C_v}and{C_p}$ denote the molar specific heat capacities of a gas at constant volume and constant pressure, respectively. Then

What will be the change in internal energy for $1 \mathrm{~g}$ of water when its phase changes from liquid phase to vapour phase? At atmospheric pressure, $1 \mathrm{~g}$ of water has a volume $1 \mathrm{~cm}^3$ in liquid phase and $1671 \mathrm{~cm}^3$ in vapour phase. (Latent heat of water is $2256 \mathrm{~J} / \mathrm{g}$.)

Statement I: In an isothermal process (quasistatic), the heat exchange between the system and surroundings takes place even though the gas has the same temperature as that of the surrounding.

Statement II: There is an infinitesimal difference in temperature between the system and the surroundings.

An ideal gas undergoing adiabatic change has the following pressure-temperature relationship

An ideal monoatomic gas given mass is heated at constant pressure. In this process, the fraction supplied heat energy used for the increase of the internal energy of the gas is

Choose the incorrect statement from the following S1 : The efficiency of a heat engine can be 1, but the coefficient of performance of a refrigerator can never be infinity S2 : The first law of thermodynamics is basically the principle of conservation of energy S3 : The second law of thermodynamics does not allow several phenomena consistent with the first law S4 : A process, whose sole result is the transfer of heat from a colder object to a hotter object is impossible

In an isothermal change, an ideal gas obeys

(A): The internal energy of an ideal gas does not change during an isothermal process.
(R): In isothermal process product of pressure and volume is constant.

In a thermodynamic process, helium gas obeys the law $\frac{{T}}{{P}^{2 / 5}}=$ constant. The heat given to the gas when temperature of 2 moles of gas is raised from $T$ to $2 T$

A gas is being compressed adiabatically. The specific heat of the gas during compression is

The ideal gas equation for an adiabatic process is:

(A): A refrigerator transfers heat from lower temperature to higher temperature.
(R): Heat cannot be transferred from lower temperature to higher temperature without doing any external work.

A vessel containing 5 litres of a gas at 0.8 M pressure, is connected to an evacuated vessel of volume 3 litres. The resultant pressure inside will be assuming whole system to the isolated.

In a cyclic process

Statement I: The internal energy of a perfect gas is entirely kinetic and depends only on absolute temperature of the gas and not on its pressure or volume.

Statement II: A perfect gas is heated keeping pressure constant and later at constant volume. For the same amount of heat the temperature of the gas at constant pressure is lower than that at constant volume.

One mole of an ideal mono atomic gas is compressed isothermally in a rigid vessel to double its pressure at room temperature, ${27^0}C$. The work done on the gas will be

In an isothermal expansion of an ideal gas, select the wrong statement.

The specific heat relation for ideal gas is

Assertion: When a bullet is fired from a gun, the bullet pierces a wooden block and stops, decreasing the temperature of the bullet and the surrounding layers of wood.
Reason: Temperature is related to the energy of motion of the bullet as a whole.

In an adiabatic process, the quantity which remains constant is

Assertion: In a thermo flask, inner surface is shiny.
Reason: Shiny surface is poor radiator of heat.

Which property of the system does not change in an adiabatic process

(A): If an ideal gas expands in vaccum in an insulated chamber, $\Delta Q, \Delta U, \Delta W$ all are zero.
(R): Temperature of gas remains constant.

In the equation for I law of thermodynamics $d Q=d u+d w$

a) $dQ$ depends on path

b) $dw$ depends on path

c) $du$ depends on path

Two Carnot engines $A$ and $B$ are operated in succession. The first one,$A$ receives heat from a source at ${T_1} = 800K$ and rejects to sink at ${T_2}K$ . The second engine $B$ receives heat rejected by the first engine and rejects to another sink at ${T_3} = 300K$. If the work outputs of two engines are equal, then the value of ${T_2}$ is

For an engine operating between ${t_1}^ \circ C$ and ${t_2}^ \circ C$, the efficiency will be

$100 \mathrm{~mol}$ of an ideal gas is heated from $10^{\circ}$ to $20^{\circ} \mathrm{C}$ keeping its (i) volume constant (ii) pressure constant. Let $\Delta U_a$ and $\Delta U_b$ denote the change in the internal energy of the gas due to process (i) and (ii), respectively. Then, which of the following shall be true?