GATE 2018 Mechanical Engineering Q31

Question

Consider steady flow of an incompressible fluid through two long and straight pipes of diameters $d_1$ and $d_2$ arranged in series. Both pipes are of equal length and the flow is turbulent in both pipes. The friction factor for turbulent flow though pipes is of the form, $f = K (Re)^{-n}$, where $K$ and $n$ are known positive constants and $Re$ is the Reynolds number. Neglecting minor losses, the ratio of the frictional pressure drop in pipe 1 to that in pipe 2, $\left(\frac{\Delta P_1}{\Delta P_2}\right)$, is given by

Accepted Answer

$\left(\frac{d_2}{d_1}\right)^{(3-n)}$

Answer

$\left(\frac{d_2}{d_1}\right)^{(5-n)}$

Answer

$\left(\frac{d_2}{d_1}\right)^{5}$

Answer

$\left(\frac{d_2}{d_1}\right)^{(5+n)}$