Venturi relation is one of application of

Explanation

The Venturi effect is a reduction in fluid pressure that occurs when a fluid flows through a constricted section of a pipe. This phenomenon is described by Bernoulli's equation, which states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or potential energy of the fluid. Option B is correct because it directly relates the Venturi effect to the principles outlined in Bernoulli's equation. Option A, the equation of continuity, is concerned with mass conservation and does not directly explain the pressure change seen in the Venturi effect. Option C, involving a 'light equation,' is not relevant to fluid dynamics. Option D, 'speed equation,' lacks specificity and does not pertain to the principles governing the Venturi effect.