$A$ water tank kept on the ground has an orifice of $2 \,mm$ diameter on the vertical side. What is the minimum height of the water above the orifice for which the output flow of water is found to be turbulent (in $\,cm$)? (Assume, $g=10 \,m/s^2, \rho_{\text{water}}=10^3 \,kg/m^3$, viscosity $=1$ centi-poise)

Water $(\rho_1=1000 \, kg/m^3)$ and kerosene $(\rho_2=800 \, kg/m^3)$ are filled to the same height in two identical cylindrical vessels. Both vessels have small holes at their bottom. The speeds of the water and kerosene coming out of their holes are $v_1$ and $v_2$ respectively. Select the correct alternative.

$A$ large vessel completely filled with water has two holes '$A$' and '$B$' at depths '$h$' and '$4h$' from the top. Hole '$A$' is a square of side '$L$' and hole '$B$' is a circle of radius '$R$'. If the same quantity of water is flowing per second from both holes,then the side of the square hole is:

Water is filled in a tank up to a height of $20 \ cm$ from the bottom of the tank. Water flows through a hole of area $1 \ mm^2$ at its bottom. The mass of the water coming out from the hole in a time of $0.6 \ s$ is (Density of water $= 1000 \ kg \ m^{-3}$ and acceleration due to gravity $= 10 \ m \ s^{-2}$) (in $g$)

$A$ large open-top water tank is completely filled with water. $A$ small hole of diameter $4 \,mm$ is made $10 \,m$ below the water level. The flow rate of water through the hole is (Acceleration due to gravity $= 10 \,m/s^2$)

Two large,identical water tanks,$1$ and $2$,kept on the top of a building of height $H$,are filled with water up to height $h$ in each tank. Both the tanks contain an identical hole of small radius on their sides,close to their bottom. $A$ pipe of the same internal radius as that of the hole is connected to tank $2$,and the pipe ends at the ground level. When the water flows out of tanks $1$ and $2$ through the holes,the times taken to empty the tanks are $t_1$ and $t_2$,respectively. If $H = (16/9) h$,then the ratio $t_1 / t_2$ is: