JEE Main Physics — Thermodynamics previous year questions with solutions.
Heat energy of $184\mathrm{kJ}$ is given to ice of mass $600g$ at $-12^{\circ}C$, Specific heat of ice is $2222.3J{\mathrm{kg}}^{–1}^{\circ}{C}^{–1}$ and latent heat of ice is $336\mathrm{kJ}{\mathrm{kg}}^{–1}$. (A) Final temperature of system will be $0^{\circ}C$ (B) Final temperature of the system will be greater than $0^{\circ}C$ (C) The final system will have a mixture of ice and water in the ratio of $5:1$ (D) The final system will have a mixture of ice and water in the ratio of $1:5$ (E) The final system will have water only Choose the correct answer from the options given below :
The molar specific heat of a gas in a process PV² = constant is:
The temperature at which the kinetic energy of oxygen molecules becomes double than its value at $27^{\circ}C$ is
If the r.m.s speed of chlorine molecule is $490m{s}^{-1}$ at ${27}^{o}C$, the r.m.s speed of argon molecules at the same temperature will be (Atomic mass of argon $=39.9u$, molecular mass of chlorine $=70.9u$)
In an Isothermal change, the change in pressure and volume of a gas can be represented for three different temperature; ${T}_{3}>{T}_{2}>{T}_{1}$ as:
A steel rod of length $1m$ and cross-sectional area ${10}^{-4}{m}^{2}$ is heated from $0^{\circ}C$ to $200^{\circ}C$ without being allowed to extend or bend. The compressive tension produced in the rod is _____$\times {10}^{4}N$. (Given Young's modulus of steel $=2\times {10}^{11}N{m}^{-2}$, coefficient of linear expansion $={10}^{-5}{K}^{-1}$ )
Two plates A and B have thermal conductivities $84W{m}^{-1}{K}^{-1}$ and $126W{m}^{-1}{K}^{-1}$ respectively. They have same surface area and same thickness. They are placed in contact along their surfaces. If the temperatures of the outer surfaces of A and B are kept at ${100}^{\circ }C$ and ${0}^{\circ }C$ respectively, then the temperature of the surface of contact in steady state is_____ $C\circ$.
The pressure of a gas changes linearly with volume from $A$ to $B$ as shown in figure. If no heat is supplied to or extracted from the gas then change in the internal energy of the gas will be 
On a temperature scale '$X$', the boiling point of water is $65^{\circ}X$ and the freezing point is $-15^{\circ}X$. Assuming that the $X$ scale is linear. The equivalent temperature corresponding to $-95^{\circ}X$ on the Fahrenheit scale would be
The initial pressure and volume of an ideal gas are${P}_{0}$ and ${V}_{0}$. The final pressure of the gas when the gas is suddenly compressed to volume$\frac{{V}_{0}}{4}$ will be: (Given $\gamma$= ratio of specific heats at constant pressure and at constant volume.)
Consider two containers $A$ and $B$ containing monoatomic gases at the same Pressure $(P)$, Volume $(V)$ and Temperature $(T)$. The gas in $A$ is compressed isothermally to $\frac{1}{8}$ of its original volume while the gas in $B$ is compressed adiabatically to $\frac{1}{8}$ of its original volume. The ratio of final pressure of gas in $B$ to that of gas in $A$ is
A gas mixture consists of $2$ moles of oxygen and $4$ moles of neon at temperature $T$. Neglecting all vibrational modes, the total internal energy of the system will be:
The pressure $(P)$ and temperature $(T)$ relationship of an ideal gas obeys the equation $P{T}^{2}=$ constant. The volume expansion coefficient of the gas will be :
A body cools in $7$ minutes from ${60}^{o}C$ to ${40}^{o}C$. The temperature of the surrounding is ${10}^{o}C$. The temperature of the body after the next $7$ minutes will be
According to law of equipartition of energy the molar specific heat of a diatomic gas at constant volume where the molecule has one additional vibrational mode is :-
The correct relation between $\gamma =\frac{{C}_{P}}{{C}_{V}}$ and temperature $T$ is :
The root mean square speed of molecules of nitrogen gas at $27^{\circ}C$ is approximately: (Given mass of a nitrogen molecule $=4.6\times {10}^{-26}\mathrm{kg}$ and take Boltzmann constant ${k}_{B}=1.4\times {10}^{-23}J{K}^{-1}$ )
Given below are two statements: Statement I: If heat is added to a system, its temperature must increase. Statement II: If positive work is done by a system in a thermodynamic process, its volume must increase. In the light of the above statements, choose the correct answer from the options given below
A hypothetical gas expands adiabatically such that its volume changes from $08$ litres to $27$ litres. If the ratio of final pressure of the gas to initial pressure of the gas is$\frac{16}{81}$ . Then the ratio of $\frac{{C}_{p}}{{C}_{v}}$ will be.
A gas is compressed adiabatically, which one of the following statement is NOT true?
The root mean square velocity of molecules of gas is
$1g$ of a liquid is converted to vapour at $3\times {10}^{5}\mathrm{Pa}$ pressure. If $10%$ of the heat supplied is used for increasing the volume by $1600{\mathrm{cm}}^{3}$ during this phase change, then the increase in internal energy in the process will be :
Heat energy of $735J$ is given to a diatomic gas allowing the gas to expand at constant pressure. Each gas molecule rotates around an internal axis but do not oscillate. The increase in the internal energy of the gas will be:
Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : If $dQ$ and $dW$ represent the heat supplied to the system and the work done on the system respectively. Then according to the first law of thermodynamics $dQ=dU-dW$. Reason R : First law of thermodynamics is based on law of conservation of energy. In the light of the above statements, choose the correct answer from the option given below :