Choose the correct option related to the specific heat at constant volume $C_V$ -

1. $C_V=\frac{1}{2}fR$           

2. $C_V=\frac{R}{\gamma -1}$

3. $C_V=\frac{C_P}{\gamma }$               

4. All of these

For a gas, $\frac{R}{C_V}=0.67$.  This gas is made up of molecules which are:                                                                   [JIPMER 2001, 02]

1. Diatomic           

2. Mixture of diatomic and polyatomic molecules

3. Monoatomic     

4. Polyatomic

${\mathrm{n}}_1$ mole of monoatomic gas is mixed with ${\mathrm{n}}_2$ mole of diatomic gas such that ${\gamma }_{mix}=1.5$, then:

1. ${\mathrm{n}}_1=2{\mathrm{n}}_2$

2. ${\mathrm{n}}_2=2{\mathrm{n}}_1$

3. $n_1=n_2$

4. $n_1=3n_2$

A monoatomic gas at a pressure p, having a volume V expands isothermally to a volume 2 V and then adiabatically to a volume 16 V. The final pressure of the gas is: (take  γ=5/3)

1. 64ρ
 

2. 32ρ
 

3. ρ/64
 

4. 16ρ 

The molar specific heats of an ideal gas at constant pressure and volume are denoted by C_P and C_V respectively. If γ=C_P/C_V and R is the universal gas constant, then CV is equal to

1. 1+γ/1-γ
2. R/(γ-1)
3. (γ-1)/R
4. γR