In an adiabatic process $90 \ J$ of work is done on the gas. The change in internal energy of the gas is ....... $J$.

$P-V$ plots for two gases during an adiabatic process are shown in the figure. Plots $(1)$ and $(2)$ correspond respectively to

$A$ gas $(\gamma = 1.3)$ is enclosed in an insulated vessel fitted with an insulating piston at a pressure of $10^5 \ N/m^2$. On suddenly pressing the piston,the volume is reduced to half the initial volume. The final pressure of the gas is:

$A$ gas is suddenly compressed to one fourth of its original volume. What will be its final pressure,if its initial pressure is $P$?

In an adiabatic expansion, the temperature of one mole of an ideal monatomic gas $(\gamma = 5/3)$ decreases from $60 \text{ K}$ to $50 \text{ K}$. The work done by the gas in the process is : (Take the universal gas constant as $R = 8.3 \text{ J mol}^{-1} \text{ K}^{-1}$) (in $\text{ J}$)

In a thermodynamic system,$\Delta U$ represents the increase in internal energy and $W$ represents the work done by the system. Which of the following statements is true?