The internal energy of the air in a room of volume $V$ at temperature $T$, with outside pressure $P$ increasing linearly with time, varies as

$540$ calories of heat converts $1$ cubic centimeter of water at $100\,^oC$ into $1671$ cubic centimeter of steam at $100\,^oC$ at a pressure of one atmosphere. Then the work done against the atmospheric pressure is nearly .......... $cal$.

The change in internal energy of a given mass of a gas,when its volume changes from $V$ to $3V$ at constant pressure $P$,is (where $\gamma$ is the ratio of the specific heat capacities of the gas).

One mole of an ideal gas undergoes a cyclic process,consisting of two isochores and two isobars. Temperatures at points $1$ and $3$ are $T_1$ and $T_3$ respectively. Find the work done by the gas over the cycle,if points $2$ and $4$ lie on the same isotherm.

An ideal monatomic gas of $n$ moles is taken through a cycle $W-X-Y-Z-W$ consisting of consecutive adiabatic and isobaric quasi-static processes,as shown in the schematic $V-T$ diagram. The volumes of the gas at $W, X,$ and $Y$ points are $64 \ cm^3, 125 \ cm^3,$ and $250 \ cm^3,$ respectively. If the absolute temperature of the gas $T_W$ at point $W$ is such that $nRT_W = 1 \ J$ ($R$ is the universal gas constant),then the amount of heat absorbed (in $J$) by the gas along the path $XY$ is $.....$

$A$ gas may expand either adiabatically or isothermally. $A$ number of $P-V$ curves are drawn for the two processes over different ranges of pressure and volume. It will be found that: