Isochoric Process - Practice Questions & MCQ

Isochoric Process- A Thermodynamic process in which volume remains constant is known as the Isochoric Process.

In this process P and T changes keeping P constant. So Gay-Lussac’s law is obeyed in this process.

  Key points in the Isochoric Process 

•  Its Equation of state is given as $\frac{P}{T}=$ constant

  $
  \text { or } \frac{P_1}{T_1}=\frac{P_2}{T_2}=\text { constant }
  $

  - P-V Indicator diagram for an isobaric process

  Its PV graph has slope= infinity (i.e $\frac{d P}{d V}=\infty$,

The above Graph represents an Isochoric increase in pressure at volume V.

 The P-V diagram for this process is a  line is parallel to the pressure line.

• Specific heat of gas during Isochoric process is given by

$
C_V=\frac{f}{2} R
$

- The bulk modulus of elasticity during Isochoric process is given by

$
K=\frac{\Delta P}{-\Delta V / V}=\frac{\Delta P}{0}=\infty
$

- Work done in Isochoric process-

$
\begin{aligned}
& \Delta W=P \Delta V \\
& \text { and as } \Delta V=0 \\
& \text { So } \Delta W=0
\end{aligned}
$

- Internal energy in Isochoric process

$
\Delta U=n C_V \Delta T=n \frac{R}{(\gamma-1)} \Delta T
$

- Heat in Isochoric process

From FLTD $\Delta Q=\Delta U+\Delta W$
But $\Delta W=0$

$
\Delta Q=\Delta U=n C_V \Delta T=n \frac{R}{(\gamma-1)} \Delta T=\frac{P_f V_f-P_i V_i}{\gamma-1}
$
 

• Examples of Isochoric process-

1. Heating of water in a pressure cooker (Valve closed)