# Water from a pipe is coming at a rate of 100 liters per minute. If the radius of the pipe is 5 cm, the Reynolds number for the flow is of the order of : $(density\; of \: water=1000 kg/m^{3}, coefficient\; of \: viscosity\: of\: water = 1mPa\; s)$  Option 1)$10^{6}$Option 2)$10^{2}$Option 3)$10^{3}$  Option 4)$10^{4}$

$\rho _{w}=10^{3}kg/m^{3}$

$\eta =1\; mPa\; s$

$r=5\; cm$

Rate of volume flow = $A.V=\pi r^{2}.V=10^{2}\frac{lit}{min}$

$\Rightarrow \pi r^{2}.V=\frac{10^{2}\times10^{-3}}{60}=\frac{1}{600}\; m^{3}/s$

$V=(\frac{1}{600}\times \frac{1}{\pi \times25\times10^{-4}})$

Re = Reynolds number =$\frac{\rho .V.D}{\eta }$

$R_e=\frac{10^{3}\times(\frac{1}{600}\times\pi \times25\times10^{-4})\times(2\times5\times10^{-2})}{10^{-3}}$

$Re\approx 10^{4}$

Option 1)

$10^{6}$

Option 2)

$10^{2}$

Option 3)

$10^{3}$

Option 4)

$10^{4}$

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