# Application of Bernoulli’s Theorem

1. The velocity of efflux of a liquid and Torricelli’s Theorem: If a small hole is present on the wall of a deep container liquid, then the velocity with which the liquid comes out through that small hole is called the velocity of efflux of a liquid.

2. Venturimeter: A venturi meter is used to measure the rate of flow of liquid through a tube. Its working principle is based on Bernoulli’s Theorem. The below figure shows the action of a venturi meter. The two ends of this tube are equally wide and the middle portion is narrow. Liquid flows through this tube in streamlines. The tube is kept horizontal.

When a liquid flows through a venturi meter, the velocity of the liquid increases at the narrow part of the tube with a consequent decrease in pressure. This decrease in pressure is measured with the help of two vertical tubes attached at the wide and narrow parties of the venturi meter.

3. Pitot Tube: A pitot tube is also used to measure the rate of flow of liquids. Its working principle is similar to that of a venturi meter. Its action also depends on Bernoulli’s theorem.

4. Sprayer or Atomizer: A sprayer or atomizer is used for spraying water, insecticides, etc. Its action also depends on Bernoulli’s theorem.