List of top Physics Questions on Thermodynamics asked in JEE Advanced

A container of height \(2\,\text{m}\), length \(2\,\text{m}\) and breadth \(1\,\text{m}\) is made of insulating vertical walls and two large area horizontal metal plates \((M_1 \text{ and } M_2)\) which extend far beyond the vertical walls in all directions. The container is partitioned into two equal chambers with a thin insulating vertical wall. The partition wall contains a small hole of cross-sectional area \(\sqrt{10}\,\text{cm}^2\) near its bottom edge. Initially the hole is closed and the left chamber of the container is completely filled with a liquid of dielectric constant \(\epsilon_r = 15\) and the right chamber is empty \((\epsilon_r = 1)\). At time \(t=0\), the hole is opened and the liquid flows from the left chamber to the right chamber. In both the chambers, the space above the liquid has \(\epsilon_r = 1\) and is maintained at atmospheric pressure. The schematic of the container at a time \(t>0\) is shown in the figure. [Given: acceleration due to gravity is \(10\,\text{ms}^{-2}\).]



The height (in m) of the liquid in left chamber at \(t=500\,\text{s}\) is:
Ten moles of an ideal monoatomic gas, initially in state \(a\) at atmospheric pressure and temperature \(T_a = 27^\circ\text{C}\), is enclosed in a metal cylinder of volume \(V_0\) fitted with a frictionless piston. The gas is suddenly compressed to state \(b\) with volume \(V_0/3\). Now, keeping the piston stationary, the cylinder is submerged in a water bath of temperature \(11^\circ\text{C}\) until the gas reaches the temperature of the water bath, which is denoted as state \(c\). Finally, while still in the water bath, the piston is brought slowly to its initial position, which is denoted as state \(f\). If \(R\) is the universal gas constant, then the correct option(s) is/are:

Given: \(9^{1/3} = 2.08\)
As shown in the figure, five Carnot engines, each with efficiency \(\eta\) and same number of cycles per unit time, are operating between six heat reservoirs. The amount of heat released per cycle by one engine is completely absorbed by the next engine. Consider \(Q_0\) to be the amount of heat absorbed per cycle by the first engine and \(W\) as the amount of total work done by all the engines per cycle, then the net efficiency of the system is found to be \[ \eta_{\mathrm{net}} = \frac{W}{Q_0} = \frac{211}{243} \] The value of \(\eta\) is _______.
A quasi-static cycle of a monoatomic ideal gas contains an isothermal process \((ab)\), followed by an isochoric process \((bc)\) and an adiabatic process \((ca)\) as shown in the figure. The volumes of the gas are \(V_1\) and \(V_2\) at \(a\) and \(b\), respectively. If the cycle has heat input \(Q_{\mathrm{in}}\) and output \(Q_{\mathrm{out}}\), then the efficiency of the cycle is defined as \[ \eta=\frac{Q_{\mathrm{in}}-Q_{\mathrm{out}}}{Q_{\mathrm{in}}} \] The correct statement(s) is/are: \[ [\text{Given: }\ln2\approx0.7] \]