Mechanical Aptitude Mechanical Aptitude Fluid Dynamics Principles Questions and Answers 3

Question 1

Which factor does NOT directly affect the buoyant force on a submerged object?

Accepted Answer

Mass of the object

Answer

Density of the fluid

Answer

Volume of the object

Answer

Gravitational acceleration

Question 2

Water flows through a horizontal pipe at a steady rate. If the pipe diameter is tripled, by what factor does the flow velocity change assuming the same volumetric flow rate?

Accepted Answer

Decreases to 1/9

Answer

Decreases to 1/3

Answer

Increases by 3

Answer

Increases by 9

Question 3

A siphon is used to transfer water from a higher tank to a lower tank. What primarily drives the flow?

Accepted Answer

Atmospheric pressure and gravity

Answer

Capillary action

Answer

Surface tension

Answer

Centrifugal force

Question 4

If the Reynolds number for flow in a pipe exceeds approximately 4,000, the flow is generally classified as what?

Accepted Answer

Turbulent

Answer

Laminar

Answer

Transitional

Answer

Static

Question 5

A fire truck pumps water through a hose and out a nozzle. Why does the water exit the nozzle at a much higher speed than it travels through the hose?

Accepted Answer

The nozzle has a smaller cross-sectional area than the hose

Answer

The pump adds extra pressure at the nozzle

Answer

Water accelerates due to gravity at the nozzle

Answer

The nozzle heats the water, increasing its speed

Question 6

Two identical containers are filled with different fluids: one with mercury and one with water. Which has greater pressure at the bottom?

Accepted Answer

The mercury container

Answer

The water container

Answer

Both have equal pressure

Answer

It depends on the container shape