Which of the following are the most important parts of a... | Agrigyan

Rheological definitions of fluids:

• Newtonian fluids strictly obey Newton's law of viscosity, exhibiting a constant viscosity and a direct linear relationship passing through the origin between shear stress ($\tau$) and velocity gradient/shear rate ($du/dy$):
  $$\tau = \mu \frac{du}{dy}$$
  Examples in dairy include water, whole milk, skim milk, and sweet whey.
• Non-Newtonian fluids show non-linear curves (shear-thinning or shear-thickening).
• Bingham plastic fluids require a yield stress before flowing.
• Ideal fluids are frictionless (zero viscosity).

Working principles of flowmeters vs pressure measuring instruments:

• An Orificemeter measures flow rate by creating a differential pressure across a constriction based directly on Bernoulli's principle.
• Venturimeter accelerates fluid through a converging-diverging throat to convert pressure head to velocity head per Bernoulli's equation.
• Pitot tube measures fluid velocity by converting kinetic energy into stagnation pressure head per Bernoulli's equation.
• Bourdon tube is a mechanical pressure gauge that operates based on the elastic mechanical deflection/uncoiling of a flattened, curved metal tube subjected to internal static fluid pressure; it does not utilize fluid velocity or Bernoulli's hydrodynamic energy equation.

Fundamental laws of hydrostatics:

• Archimedes' principle governs buoyant upward force on submerged bodies.
• Bernoulli's principle relates pressure, velocity, and elevation along a streamline in moving fluids.
• Pascal's Law states that in a fluid at rest in a closed system, the pressure exerted at any point is transmitted equally and undiminished in all directions throughout the fluid ($P_x = P_y = P_z$).
• Continuity principle governs mass conservation in fluid conduits ($A_1 v_1 = A_2 v_2$).