First Law of Thermodynamics

An ideal gas is allowed to expand freely against vacuum in a rigid insulated container. The gas undergoes

When heat is supplied to the system then $\Delta Q$ is ____ and $\Delta Q$ is ____ when heat is extracted from the system. Choose the appropriate option.

The ratio of work done by an ideal monoatomic gas to the heat supplied to it in an isobaric process is

When a system is taken from state $i$ to state $f$along the path $iaf$, it is found that $Q=50 \mathrm{cal}$ and $W=20 \mathrm{cal}$. Along the path $ibf$, $Q=36 \mathrm{cal}$ and $W$along the path $ibf$ is

The $P-V$ diagram of a system undergoing thermodynamic transformation is shown in figure. The work done by the system in going from $A\to B\to C$ is $30 \mathrm{J}$ and $40\mathbf{ }\mathrm{J}$ heat is given to the system. The change in internal energy between $A$ and $C$ is

Two moles of a monatomic ideal gas are taken through a cyclic process shown on the $P-T$ diagram. The process $\mathrm{CA}$ is represented as $PT$ = constant. If the efficiency of the given cyclic process is $1-\frac{x}{12ln2+15}$, then what is the value of $x$?

$1 \mathrm{mole}$ of rigid diatomic gas performs a work of $\frac{\mathrm{Q}}{5}$ when heat $\mathrm{Q}$ is supplied to it. The molar heat capacity of the gas during this transformation is $\frac{\mathrm{xR}}{8}.$ The value of $\mathrm{x}$ is ________ .

A monatomic ideal gas undergoes a process $ABC$. The heat given to the gas is,

An ideal gas undergoes change in its state from the initial state $l$ to the final state $F$ via two possible paths as shown below. Then,

One mole of an ideal monatomic gas is taken through a semicircular thermodynamic process $ACB$ shown in the $P–V$ diagram. The heat supplied to the system is

The workdone on the system in changing the state of a gas adiabatically from equilibrium state $A$ to equilibrium state $B$ is $32.4 \mathrm{J}$. If the gas is taken from state $A$ to $B$ through another process in which the net heat absorbed by the system is $13.5 \mathrm{cal}$, then the net workdone by the system in the later case is $\left(1 \mathrm{cal}=4.2 \mathrm{J}\right)$

An electric heater supplies heat to a system at a rate of $100 W\mathit{.}$ If the system performs Work at a rate of $60$ joules per second, the rate at which internal energy changes is

Two cylinders $A$ and $B$ of equal capacity are connected to each other via a stopcock. A contains an ideal gas at standard temperature $\left(T_1\right)$ and pressure. $B$ is empty. Then the entire system is thermally insulated. The stopcock is suddenly opened. After the gas reaches equilibrium the temperature $\left(T_2\right)$ of the gas measured. Which of the following is correct?

$1 \mathrm{gm}$ of water at $100 °\mathrm{C}$, is completely converted to steam at $100 °\mathrm{C}$, occupies $1800 \mathrm{cc}$. The increase in the internal energy of the molecules is:
(take the pressure $={10}^5 \mathrm{Pa}$, Latent heat of vaporisation $\left(L\right)=540 \mathrm{cal} {\mathrm{gm}}^{-1},1\mathrm{cal}=4.2 \mathrm{J}$)

A graph of pressure $\left(P\right)$  against volume $\left(V\right)$ of an ideal gas undergoing an isothermal process is ____

As shown in the figure, the amount of heat absorbed along the path $ABC$ is $90 \mathrm{J}$ and the amount of work done by the system is $30 \mathrm{J}$. If the amount of work done along the path $ADC$ is $20 \mathrm{J}$ the amount of heat absorbed will be:

When a system is taken from state $\mathrm{i}$ to state $\mathrm{f}$ along the path $\mathrm{iaf}$, it is found that $Q\mathit{=}50 \mathrm{cal}$ and $W=20 \mathrm{cal}$. Along the path $\mathrm{ibf}$, $Q=36 \mathrm{cal}$. Work (in $\mathrm{cal}$) along the path $\mathrm{ibf}$ is-

In thermodynamic process pressure of a fixed mass of gas is changed in such a manner that the gas releases $30$ joule of heat and $18$ joule of work was done on the gas. If the initial internal energy of the gas was $60$ joule, then, the final internal energy (in J) will be:

One mole of a perfect gas in a cylinder fitted with a piston has a pressure $P$, volume $V$ and temperature $T$. If the temperature is increased by $1 \mathrm{K}$ keeping pressure constant, the increase in volume is :-

A thermodynamic process is shown in the figure. The pressures and volumes corresponding to some points in the figure are: $P_{\mathrm{A}}=3\times {10}^4 \mathrm{Pa}\text{,} P_{\mathrm{B}}=8\times {10}^4 \mathrm{Pa}$ and $V_{\mathrm{A}}=2\times {10}^{-3} {\mathrm{m}}^3\text{,} V_{\mathrm{D}}=5\times {10}^{-3} {\mathrm{m}}^3$. In process $AB\text{,} 600 \mathrm{J}$ of heat is added to the system and in process $BC\text{,} 200 \mathrm{J}$ of heat is added to the system. The change in internal energy(in $\mathrm{J}$) of the system in the process $AC$ would be,