$A$ liquid flows through a horizontal tube. The velocities of the liquid in the two sections,which have areas of cross-section $A_1$ and $A_2$,are $v_1$ and $v_2$ respectively. The difference in the levels of the liquid in the two vertical tubes is $h$.

$A$ $U$-tube has a left limb with a cross-sectional area one-quarter that of the right limb. The tube contains mercury (density $13.6 \text{ g/cm}^3$). The level of mercury in the narrow (left) limb is at a distance of $36 \text{ cm}$ from the upper end of the tube. What will be the rise in the level of mercury in the right limb if the left limb is filled to the top with water (in $\text{ cm}$)? (Density of water = $1 \text{ g/cm}^3$)

Two cylindrical vessels of equal cross-sectional area $16\,cm^{2}$ contain water up to heights $100\,cm$ and $150\,cm$ respectively. The vessels are interconnected so that the water levels in them become equal. The work done by the force of gravity during the process is $......J$. [Take density of water $= 10^{3}\,kg/m^{3}$ and $g = 10\,m/s^{2}$]

Give the limitations and uses of turbulence.

Consider the following statements:
$A.$ Surface tension arises due to extra energy of the molecules at the surface as compared to the molecules in the interior of a liquid.
$B.$ As the temperature of a liquid rises, the coefficient of viscosity increases.
$C.$ As the temperature of a gas increases, the coefficient of viscosity increases.
$D.$ The onset of turbulence is determined by Reynolds number.
$E.$ In a steady flow, two streamlines never intersect.
Choose the correct answer from the options given below:

$A$ horizontal fire hose with a nozzle of cross-sectional area $\frac{5}{\sqrt{21}} \times 10^{-3} \text{ m}^2$ delivers a cubic metre of water in $10 \text{ s}$. What will be the maximum possible increase in the temperature of water while it hits a rigid wall (neglecting the effect of gravity) (in $^{\circ} \text{C}$)?