Consider a steady flow of oil in a pipeline. The cross-sectional radius of the pipeline decreases gradually as r = r0e-ax where a = \(\frac{1}{3}\) m-1 and x is the distance from the pipeline inlet. If R1 is the Reynold's number for a certain pipeline cross-section at a distance x1 meter from the inlet and R2 is for distance (x1 + 3) metre, then the ratio \(\rm\frac{R_1}{R_2}\) is
1
\(\frac{1}{e}\)
2
e
3
\(\frac{1}{e^3}\)
4
\(\frac{1}{e^6}\)