Practice Questions

Statement 2 is correct while statement 1 is incorrect. Piezometer is the simplest form of manometer for measuring gauge pressures. It measures only the gauge pressures. It would not work for negative gauge pressures, because air would flow into the container through the tube.. Thixotropic fluids require decreasing stress and exhibit a decrease in viscosity with time.

Piezometer is used to measure small variation of pressure above or below ambient pressure.

Thixotropic fluid exhibits decrease in viscosity with time.

At the stagnation point in a flow field, the velocity of fluid is zero. This is because it is the point where the static pressure is highest and the velocity is at its minimum.

Euler's equation of motion relates velocity, pressure, and density of a moving, non-viscous, homogeneous, and incompressible fluid. It is based on the conservation of linear momentum for a flow with no external forces except gravity and pressure. The integration of the equation gives Bernoulli's equation in the form of energy per unit weight of the fluid.

linear momentum conservation for the flow of an inviscid fluid

linear momentum conservation for a real fluid

Dynamic pressure represents the pressure rise when the fluid in motion is brought to a stop isentropically i.e  $\frac {\rho V^2}{2}$

A venturi-meter measures fluid flow rate through a pipe. It has a smaller convergent portion and larger divergent portion to avoid energy loss due to separation. As the liquid flows through the converging part, velocity increases and pressure decreases according to Bernoulli's theorem. Velocity reaches its maximum and pressure reaches its minimum at the throat. As the liquid flows through the divergent part, velocity decreases and pressure increases

head constant at every point in abucket of water. This is because the pressure heery poir elevation head remain constant for all points in the bucket. The piezometric head is given by the sum of pressure head and elevation head.

The value of coefficient of discharge for an external cylindrical mouthpiece when the pipe is flowing full is 0.86.

According to Bernoulli's principle, an increase in fluid speed leads to a decrease in pressure and/or a decrease in fluid potential energy

Increase in pressure and/or increase in fluid's potential energy

Decrease in pressure and/or increase in fluid's potential energy

Increase in pressure and/or decrease in fluid's potential energy

Decrease in pressure and/or decrease in fluid's potential energy

Bernoulli's Equation states that in a steady, ideal flow of an incompressible fluid, the total energy at any point of the fluid is constant. The assumptions taken in the Bernoulli theorem are that the fluid is ideal, steady, incompressible, and irreversible, with no external force acting on the liquid except gravity. The option that is NOT an assumption taken in the Bernoulli theorem is "The flow is rotational."

Mechanics is the science that deals with the effects of forces on objects. It has two parts: Statics and Dynamics. Statics deals with the equilibrium of bodies under the action of forces, where the body can be at rest or in uniform motion and the net force on the body is zero. Dynamics deals with the motion of the body under the action of force, where it deals with accelerated bodies.

Bernoulli's theorem is a fundamental principle in fluid dynamics that describes the behavior of fluid flow. It states that in a streamline flow, the sum of the pressure energy, kinetic energy, and potential energy per unit volume remains constant. This principle is based on the conservation of a specific quantity, ensuring that energy transformations within the fluid are accounted for.

Coefficient of velocity (Cv) is the ratio of actual velocity of jet at vena-contracta to theoretical velocity. Coefficient of discharge (Cd) is the ratio of actual discharge through an orifice to theoretical discharge. Coefficient of contraction (Cc) is the ratio of area of jet at vena-contracta to area of orifice. Cd=Cv x Cc.

Area of jet at vena contracta to the area of orifice

Actual discharge through an orifice to the area of orifice

Actual velocity of jet at vena contracta to the theoretical velocity

Actual discharge through an orifice to the theoretical discharge

A moving fluid experiences various forces including gravity, pressure, viscosity, surface tension, turbulence, and compressibility. The net force acting on the fluid is the sum of all these forces

Pitot tube	Flow static pressure
Micro-manometer	Flow stagnation pressure
Pipe bend meter	A rate flow (indirect)
Wall pressure tap	Differential pressure

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