FLUID.This means that in steady flow the sum of all forms of mechanical energy in a fluid along a streamline is the same at all points on that streamline.From Bernoulli's principle\(P + \frac{1}{2}\rho {v^2} + \rho gh = constant\)i.e., \({P_1} + \frac{1}{2}\rho v_1^2 + \rho g{h_1} = {P_2} + \frac{1}{2}\rho v_2^2 + \rho g{h_2}\)Pascal's law states that any pressure applied to a fluid inside a closed system will transmit that pressure equally in all directions throughout the fluid. Therefore option 1 is incorrect.Archimedes states that “When a body is immersed in a liquid, an UPWARD thrust, equal to the weight of the liquid displaced, ACTS on it.”. Therefore option 2 is incorrect.From above it is CLEAR that Bernoulli's equation relates the pressure difference between two points in a pipe to changes in Kinetic as well as potential energy. Therefore option 3 is correct.Torricelli's law states that the VELOCITY of efflux of fluid is equal to the velocity which a body acquires in falling freely from the free liquid surface to the orifice. Therefore option 4 is incorrect.