$1 \rightarrow 2 :$ isochoric process
$2 \rightarrow 3 :$ straight line on $P-V$ diagram
$3 \rightarrow 1 :$ isobaric process
The average molecular speed of the gas in the states $1, 2$ and $3$ are in the ratio
$(A)$ the mean free path of the molecules decreases.
$(B)$ the mean collision time between the molecules decreases.
$(C)$ the mean free path remains unchanged.
$(D)$ the mean collision time remains unchanged.
(Take $\gamma$ for nitrogen and $CO_2$ as $1.4$ and $1.3$ respectively)
