Question

Venturimeter works on the principle of

• A. Law of conservation of mass
• B. Law of conservation of energy
• C. Law of conservation of force
• D. Law of conservation of velocity

Hint:

Bernoulli's theorem = Conservation of Energy (Venturimeter, Orificemeter, Pitot tube). Continuity equation = Conservation of Mass.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
A Venturimeter is a differential pressure flowmeter operating on Bernoulli's theorem of mechanical energy conservation.
Key Formula or Approach:
\[ \frac{p_1}{\rho g} + \frac{v_1^2}{2g} + z_1 = \frac{p_2}{\rho g} + \frac{v_2^2}{2g} + z_2 \]

Step 2: Detailed Explanation:
A Venturimeter accelerates fluid through a converging nozzle into a narrow throat.
By Bernoulli's principle (which is the mathematical formulation of the Law of Conservation of Energy for steady, frictionless, incompressible fluid flow):
An increase in kinetic velocity head at the throat causes a corresponding drop in piezometric pressure head.
The measured differential pressure between the inlet and throat allows direct calculation of discharge.

Step 3: Final Answer:
Thus, Venturimeter works on the Law of conservation of energy, corresponding to option (B).