Can two isothermal curves cut each other?

1.	Never
2.	Yes
3.	They will cut when the temperature is 0°C.
4.	Yes, when the pressure is equal to the critical pressure.

An ideal gas A and a real gas B have their volumes increased from V to 2 V under isothermal conditions. The increase in internal energy 

(1) Will be same in both A and B

(2) Will be zero in both the gases

(3) Of B will be more than that of A

(4) Of A will be more than that of B

The latent heat of vaporisation of water is \(2240~\text{J/gm}\). If the work done in the process of expansion of \(1~\text{g}\) is \(168~\text{J}\), then the increase in internal energy is:
1. \(2408~\text{J}\)
2. \(2240~\text{J}\)
3. \(2072~\text{J}\)
4. \(1904~\text{J}\)

If $\gamma$ denotes the ratio of two specific heats of a gas, the ratio of slopes of adiabatic and isothermal PV curves at their point of intersection is 

(1) $\frac{1}{\gamma }$

(2) $\gamma$

(3) $\gamma -1$

(4) $\gamma +1$

Air in a cylinder is suddenly compressed by a piston, which is then maintained at the same position. With the passage of time 

(1) The pressure decreases

(2) The pressure increases

(3) The pressure remains the same

(4) The pressure may increase or decrease depending upon the nature of the gas

A polyatomic gas \(\left(\gamma = \frac{4}{3}\right)\) is compressed to \(\frac{1}{8}\) of its volume adiabatically. If its initial pressure is \(P_0,\) its new pressure will be:

For adiabatic processes $\left(\gamma =\frac{C_p}{C_v}\right)$ 

(1) $P^{\gamma }V$ = constant

(2) $T^{\gamma }V$ = constant

(3) $T{V}^{\gamma -1}$ = constant

(4) $T{V}^{\gamma }$ = constant

One mole of helium is adiabatically expanded from its initial state $(P_i,V_i,T_i)$ to its final state $(P_f,V_f,T_f)$. The decrease in the internal energy associated with this expansion is equal to

(1) $C_V(T_i-T_f)$

(2) $C_P(T_i-T_f)$

(3) $\frac{1}{2}(C_P+C_V)(Ti-T_f)$

(4) $(C_P-C_V)(T_i-T_f)$

A diatomic gas initially at 18°C is compressed adiabatically to one-eighth of its original volume. The temperature after compression will be 

(1) 10°C

(2) 887°C

(3) 668 K

(4) 144°C