Thermodynamics Question 6

Question 6 - 25 January - Shift 2

Match List I with List II :

List I List II
A. Isothermal math
Process
I. Work done by the
gas decreases
internal energy
B. Adiabatic Process II. No change in
internal energy
C. Isochoric Process III. The heat absorbed
goes partly to
increase internal
energy and partly
to do work
D. Isobaric Process IV. No work is done
on or by the gas

Choose the correct answer from the options given below:

(1) A-II, B-I, C-III, D-IV

(2) A-II, B-I, C-IV, D-III

(3) A-I, B-II, C-IV, D-III

(4) A-I, B-II, C-III, D-IV

Show Answer

Answer: (2)

Solution:

Formula: Isothermal process, Isobaric process, Isochoric process, Adiabatic process

$\Delta U=nC_v \Delta T$

For isothermal process $T$ is constant

So $\Delta U=0$

$A \longrightarrow II$

Adiabatic process

$\Delta Q=0$

$\Delta Q=\Delta U+\Delta W$

$ \Delta U=-\Delta W $

Work done by gas is positive

So $\Delta U$ is negative

$B \longrightarrow I$

For Isochoric process $\Delta W=0$

$C \longrightarrow IV$

For Isobaric process

$\Delta W=P \Delta V \neq 0$

$\Delta U=nC_V \Delta T \neq 0$

Heat absorbed goes partly to increase internal energy and partly do work.