One mole of an ideal monoatomic gas undergoes the following four reversible processes:

Step $1$ It is first compressed adiabatically from volume $8.0 \,m ^{3}$ to $1.0 \,m ^{3}$.

Step $2$ Then expanded isothermally at temperature $T_{1}$ to volume $10.0 \,m ^{3}$.

Step $3$ Then expanded adiabatically to volume $80.0 \,m ^{3}$.

Step $4$ Then compressed isothermally at temperature $T_{2}$ to volume $8.0 \,m ^{3}$.

Then, $T_{1} / T_{2}$ is

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

$Assertion :$ In adiabatic compression, the internal energy and temperature of the system get decreased.
$Reason :$ The adiabatic compression is a slow process.

An ideal gas at pressure $P$ and volume $V$ is expanded to volume$ 2V.$ Column $I$ represents the thermodynamic processes used during expansion. Column $II$ represents the work during these processes in the random order.:

The correct matching of column $I$ and column $II$ is given by 

What is an isochoric process and cyclic process ? Write the first law of thermodynamics for an ideal gas.

A certain amount of gas of volume $V$ at $27^{o}\,C$ temperature and pressure $2 \times 10^{7} \;Nm ^{-2}$ expands isothermally until its volume gets doubled. Later it expands adiabatically until its volume gets redoubled. The final pressure of the gas will be  (Use $\gamma=1.5$ )