Venturi Discharge Formula — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
Venturi Discharge Formula This formula applies to the steady, incompressible, and ideal flow of a fluid through a Venturi meter, derived from Bernoulli's principle. Apply the Continuity Equation: A 1 v 1 = A 2 v 2 = Q . Apply Bernoulli's Equation between the inlet (1) and the throat (2): P 1 + 1 2 v 1 2 = P 2 + 1 2 v 2 2 . Rearrange to find the pressure difference: P = P 1 - P 2 = 1 2 (v 2 2 - v 1 2) . Substitute v 1 and v 2 using the continuity equation ( v 1 = Q/A 1 , v 2 = Q/A 2 ) and solve for Q . P > 0 > 0 A 1 > A 2 Assuming the fluid is compressible (which invalidates the use of constant density ). Forgetting that the pressure difference P is the driving force, not the absolute pressure. Incorrectly applying the continuity equation, especially when calculating velocity at the throat.