Question

Bernoulli’s principle is based on the law of conservation of
A. Angular momentum
B. Linear momentum
C. Mass
D. Energy

Answer 1

Hint: The given principle is very important in fluid mechanics and it also has various applications. You may recall the mathematical expression representing this principle. From that you will clearly understand which conservation law is used for deriving the expression. Hence, you will find the answer.

Complete step by step solution:
Bernoulli’s principle is actually based on the law of conservation of energy. Even the very derivation of Bernoulli's equation is done based on the conservation of energy. A simplified statement of this principle would be, ‘The sum total of all the forms of energy that a fluid can possess along a streamline would be constant at all points on that streamline’. Or in other words, the total mechanical energy that includes the kinetic energy, gravitational potential energy and pressure energy of the fluid will be a constant by Bernoulli’s principle. Mathematically it can be expressed as,
$p+\dfrac{1}{2}\rho {{v}^{2}}+\rho gh=k$
Where, p is the energy associated with the fluid flow, v is the velocity of the fluid, $\rho $is the density of the fluid and h is the height of the container.
Hence, we found that Bernoulli's principle is based on the law of conservation of energy.

So,the correct answer is Option (D).

Note:
From Bernoulli's equation, we are actually getting a very clear insight on the balance between fluid pressure, velocity and also the elevation. This principle has various applications. It could be used for the approximation of pressure as well as speed of the fluid. It also has application in theory of ocean surface waves and acoustics. Other applications include, venturi meter, our tendency to fall towards a moving train and even the working of an aeroplane.