Question

The fixed mass ‘m’ of a gas is subjected to transformation of states from K to L to M to N and back to K as shown in figure:

The succeeding operations that enable the transformation states are:

• A. Heating, cooling, heating, cooling
• B. Cooling, heating, cooling, heating
• C. Heating, cooling, cooling, heating
• D. Cooling, heating, heating, cooling

Answer 1

The correct option is C Heating, cooling, cooling, heating

When the gas is subjected to transformation from K to L
it is an isobaric pressure so, P = constant
$\frac{T}{V}$ = constant
thus,
$\frac{T_K}{V_K}=\frac{T_L}{V_L}$
$T_K=\frac{V_K}{V_L}{T}_L$
From graph we can say that $V_L>V_K$
Hence, $T_L>T_K$
Heating takes place here
Now for L to M,
Isochoric process,$\frac{T}{P}$ = constant
$\frac{T_M}{P_M}=\frac{T_L}{P_L}$
$T_M=\frac{P_M}{P_L}{T}_L$
we also know, $P_L>P_M$
Hence, $T_L>T_M$ so the process is cooling
Similarly for M to N and N to K which respectively will be cooling and heating so the correct order is option (c)