Mechanical Aptitude Mechanical Aptitude Fluid Dynamics Principles 3

Question 1

Oil with a specific gravity of 0.85 is resting on top of water. What does this tell you about the oil?

Accepted Answer

Oil is less dense than water and floats

Answer

Specific gravity less than 1.0 means the fluid is less dense than water, so oil floats on the water surface.

Question 2

A Venturi meter is used to measure:

Accepted Answer

Flow rate through a pipe

Answer

A Venturi meter measures flow rate by detecting the pressure difference between a wide section and a narrow throat section of a pipe.

Question 3

At what point in a piping system is cavitation most likely to occur?

Accepted Answer

Where pressure drops below the fluid's vapor pressure

Answer

Cavitation occurs when local pressure falls below the vapor pressure of the fluid, causing vapor bubbles to form.

Question 4

A tank has a hole near its base. As the water level in the tank drops, what happens to the velocity of water exiting the hole?

Accepted Answer

Velocity decreases

Answer

By Torricelli's theorem, exit velocity = √(2gh), so as height h decreases, exit velocity decreases.

Question 5

In a hydraulic system, which of the following best describes Pascal's Law?

Accepted Answer

Pressure applied to a confined fluid is transmitted equally in all directions

Answer

Pascal's Law states that pressure changes applied to an enclosed fluid are transmitted undiminished throughout the entire fluid.

Mechanical Aptitude Test Practice Test