What is the value of Reynolds number for turbulent flow?

What is the value of the Reynolds number $(R_e)$ for unsteady flow?

$A$ fluid of density $\rho$ and viscosity $\eta$ is flowing through a pipe of diameter $d$, with a velocity $v$. The Reynolds number is:

Two capillary tubes of same length each of $50 \ cm$ but of different radii $4 \ mm$ and $2 \ mm$ are connected in series. When water flows,the pressure difference between the ends of the arrangement is $P$. Then the pressure difference between the ends of the first tube is

For which of the following Reynolds numbers is a flow considered streamlined (laminar)?

$A$ horizontal pipeline carrying gasoline has a cross-sectional diameter of $5 \,mm$. If the viscosity and density of the gasoline are $6 \times 10^{-3} \,Poise$ and $720 \,kg/m^3$ respectively, the velocity after which the flow becomes turbulent is: