Question

Match the thermodynamic processes taking place in a system with the correct conditions. In the table : $\Delta Q$ is the heat supplied, $\Delta W$ is the work done and $\Delta U$ is change in internal energy of the system :

Process		Condition
(I)	Adiabatic	(A)	$\Delta W=0$
(II)	Isothermal	(B)	$\Delta Q=0$
(III)	Isochoric	(C)	$\Delta U\ne 0,\Delta W\ne 0$ $\Delta Q\ne 0$
(IV)	Isobaric	(D)	$\Delta U=0$

• A. $I-B,II-D,III-A,IV-C$
• B. $I-B,II-A,III-D,IV-C$
• C. $I-A,II-A,III-B,IV-C$
• D. $I-A,II-B,III-D,IV-D$

Answer 1

Answer: (A)

(I) Adiabatic process $\Rightarrow \Delta Q=0$
No exchange of heat takes place with surroundings
(II) Isothermal proess $\Rightarrow$ Temperature remains
$\text{ constant }(\Delta T=0)$
$\Delta u=\frac{F}{2}nR\Delta T\Rightarrow \Delta u=0$
No change in internal energy $[\Delta u=0]$
(III) Isochoric process Volume remains constant
$\Delta V=0$
$W=\int P.dV=0$
Hence work done is zero.
(IV) Isobaric process $\Rightarrow$ Pressure remains constant
$W=P.\Delta V\ne 0$
$\Delta u=\frac{F}{2}nR\Delta T=\frac{F}{2}[P\Delta V]\ne 0$
$\Delta Q=n{C}_p\Delta T\ne 0$