Question

Which of the following principles shows that if you increase air speed its pressure will decrease?
A. Darwin principle
B. Einstein principle
C. Bohr principle
D. Bernoulli’s principle

Answer 1

Hint : As a very first step, one could read the question well along with the given options. Then we could recall the concept under which the mentioned condition comes and then the principle among the given ones that comes under that concept and hence the answer.

Complete step-by-step solution:
In the question we are asked to name the principle that shows that on increasing air speed the pressure is decreased. The question is followed by four options with names of certain principles and we are supposed to find the right one among them.
It is Bernoulli's principle that shows the condition given in the question.
In order to understand this, let us recall the basic statement of this principle given by,
The increase in the speed of a certain fluid occurs simultaneously with the decrease in static pressure or a decrease in static pressure or even a decrease in the potential energy of the fluid.
Therefore, we found that Bernoulli's principle shows the given condition mentioned in the question.
Hence, option D is correct.

Note: This very principle was put forward by Daniel Bernoulli and hence the very name. Also, this principle is known to be applicable for only the isentropic flows. Also, when the effects due to the irreversible processes and non-adiabatic processes are small, this is neglected.