Embibe Experts Solutions for Chapter: Thermodynamics, Exercise 7: Exercise (Previous Year Questions)

The molar specific heat at constant pressure of an ideal gas is $\left(\frac{7}{2}\right)R$. The ratio of specific heat at constant pressure to that at constant volume is 

A monoatomic gas at pressure $P_1$ and volume $V_1$ is compressed adiabatically to $\frac{1}{8}$ th its original volume. What is the final pressure of the gas:-

A monatomic gas at a pressure $P$, having a volume $V$ expands isothermally to a volume $2V$ and then adiabatically to a volume $16V$. The final pressure of the gas is (take $\gamma =\frac{5}{3}$) 

A refrigerator works between $4 °\mathrm{C}$ and $30 °\mathrm{C}$. It is required to remove $600 \mathrm{calories}$ of heat every $\mathrm{second}$ in order to keep the temperature of the refrigerated space constant. The power required is [take $1 \mathrm{cal}=4.2 \mathrm{Joule}$].

A gas is compressed isothermally to half its initial volume. The same gas is compressed separately through an adiabatic process until its volume is again reduced to half. Then

One mole of an ideal monatomic gas undergoes a process described by the equation $P{V}^3=$ constant. The heat capacity of the gas during this process is

The efficiency of a heat engine working between the freezing point and boiling point of water is

The change in entropy of $1 \mathrm{kg}$ of nitrogen gas in an isobaric process when its temperature changes from $400 \mathrm{K} \text{to }800 \mathrm{K}$ is