JEE Main · 2021 · 17 Mar 2021 · Shift 1 · Heat & Thermodynamics

A cylindrical tube $AB$ of length $l$, closed at both ends contains an ideal gas of 1 mol having molecular weight $M$. The tube is rotated in a horizontal plane with constant angular velocity $\omega$ about an axis perpendicular to $AB$ and passing through the edge at end A, as s …

Rods $x$ and $y$ of equal dimensions but of different materials are joined as shown in figure. Temperatures of end points $A$ and $F$ are maintained at $100^{\circ }\mathrm{C}$ and $40^{\circ }\mathrm{C}$ respectively. Given the thermal conductivity of rod x is three …

The volume of an ideal gas increases 8 times and temperature becomes $(1/4{)}^{\text{th }}$ of initial temperature during a reversible change. If there is no exchange of heat in this process ( $\Delta \mathrm{Q}=0$ ) then identify the gas from the following options (Assuming …

Consider two boxes containing ideal gases A and B such that their temperatures, pressures and number densities are same. The molecular size of A is half of that of B and mass of molecule A is four times that of B. If the collision frequency in gas B is …

An insulated cylinder of volume $60{\mathrm{cm}}^3$ is filled with a gas at $27^{\circ }\mathrm{C}$ and 2 atmospheric pressure. Then the gas is compressed making the final volume as $20{\mathrm{cm}}^3$ while allowing the temperature to rise to $77^{\circ }\mathrm{C}$. The fin …

The r.m.s speed of oxygen molecules at $47^{\circ }\mathrm{C}$ is equal to that of the hydrogen molecules kept at $\_\_\_\_$ ${}^{\circ }\mathrm{C}$. (Mass of oxygen molecule/mass of hydrogen molecule=32/2)