One mole of an ideal gas in initial state A undergoes a cyclic process $A B C A$, as shown in the figure.…

One mole of an ideal gas in initial state A undergoes a cyclic process $A B C A$, as shown in the figure. Its pressure at $A$ is $p_0$. Choose the correct option(s) from the following
  1. Internal energies at $A$ and $B$ are the same
  2. Work done by the gas in process $A B$ is $p_0 V_0 \ln 4$
  3. Pressure at $C$ is $\frac{p_0}{4}$
  4. Temperature at $C$ is $\frac{T_0}{4}$

Solution

$ \begin{aligned} & T_A=T_B \quad \therefore U_A=U_B \\ & W_{A B}=(1)(R) T_0 \ln \left(\frac{V_f}{V_i}\right) \\ & =R T_0 \ln \left(\frac{4 V_0}{V_0}\right) \\ & =p_0 V_0 \ln (4) \end{aligned} $ Information regarding $p$ and $T$ at $C$ can not be obtained from the given graph. Unless it is mentioned that line $B C$ passes through origin or not. Hence, the correct options are (a) and (b).

Asked in: JEE Advanced 2010 (Paper 1)

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