GATE Civil Engineering (CE) 2019 Shift 2 Solved Paper

Consider the reactor shown in the figure. The concentration (in $\mathit{m}\mathit{g}/\mathit{l})$ of a compound in the influent and effluent are ${\mathit{C}}_0$ and $\mathit{C}$, flow rate through the reactor is $\mathit{Q}{\mathit{m}}^3/\mathit{h}$ respectively. The compound is degraded in the reactor following the first order reactions. The mixing condition of the reactor Complete Mix Flow Reactor (CMFR) or a plug-flow reactor (PFR). The length of the reactor can be adjusted in these two mixing conditions to L $\mathit{C}\mathit{M}\mathit{F}\mathit{R}$ and ${\mathit{L}}_{\mathit{P}\mathit{E}\mathit{R}}$ while keeping the cross-section of the reactor constant. Assuming steady state and for $\mathit{C}/{\mathit{C}}_0=0.8$, the value of ${\mathit{L}}_{\mathit{C}\mathit{M}\mathit{F}\mathit{R}}/\mathit{L}\mathit{P}\mathit{E}\mathit{R}$ (round off to 2 decimal places) is ___________