The instrument fitted in the carburetor of an automobile to provide the correct mixture of air and fuel necessary for combustion works on which of the following principles?

Consider the following equation of Bernoulli's theorem: $P + \frac{1}{2}\rho V^2 + \rho gh = K$ (constant). The dimensions of $K/P$ are the same as those of which of the following?

$A$ closed pipe containing a liquid showed a pressure $P_1$ by gauge. When the valve was opened,the pressure was reduced to $P_2$. The speed of water flowing out of the pipe is ( $\rho=$ density of water )

$A$ wind with speed $40 \ m/s$ blows parallel to the roof of a house. The area of the roof is $250 \ m^2$. Assuming that the pressure inside the house is atmospheric pressure,the force exerted by the wind on the roof and the direction of the force will be $(\rho_{air} = 1.2 \ kg/m^3)$.

What is the nature of the pressure-distance graph for the pipe shown in the figure?

The figures below show water flowing through a horizontal pipe from left to right. Note that the pipe in the middle is narrower. Choose the most appropriate depiction of water levels in the vertical pipes.