Bernoulli's theorem states that in a steady, ideal flow of an incompressible fluid, the total energy at any point of the fluid is constant. The total energy consists of pressure energy, kinetic energy and potential energy or datum energy. Assumptions made in the derivation of Bernoulli's equation (i) If the fluid is ideal, i.e., Viscosity is zero. (ii) If the flow is steady (iii)If the flow is incompressible. (iv) If the flow is irrotational.