Mechanical Aptitude Fluid Dynamics Principles Flashcards
7 cards from real MECHANICAL APTITUDE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Mechanical Aptitude Fluid Dynamics Principles flashcards as text
An airplane wing generates lift primarily because:
Answer: Air moves faster over the curved top surface, reducing pressure there
The wing's curved upper surface causes air to speed up, which by Bernoulli's principle reduces pressure on top relative to the bottom, generating lift.
In a pipe system, what is the purpose of a check valve?
Answer: To prevent backflow of fluid
A check valve is a one-way valve that allows fluid to flow in only one direction, automatically closing if flow tries to reverse.
A fluid flowing through a pipe that makes a 90° bend will experience which of the following?
Answer: Additional pressure loss due to the change in flow direction
Bends, elbows, and fittings create additional losses called minor losses due to turbulence and flow separation at the direction change.
What is the definition of 'flow rate' in a fluid system?
Answer: The volume of fluid passing a point per unit of time
Flow rate (volumetric) is the volume of fluid that passes through a cross-section per unit time, commonly expressed in gallons per minute (GPM) or liters per second.
Which of the following describes the function of a pressure relief valve in a hydraulic circuit?
Answer: It limits maximum system pressure to protect components
A pressure relief valve opens automatically when system pressure exceeds a set limit, diverting fluid back to the reservoir to protect pumps and components.
Compared to water, a very viscous oil flowing through the same pipe at the same velocity is more likely to exhibit:
Answer: Laminar flow
Higher viscosity increases resistance to turbulence; at the same velocity, viscous oils have lower Reynolds numbers and are more likely to flow laminarly.
A hydraulic cylinder with a bore of 3 inches is supplied with oil at 1,000 psi. Approximately what force does the cylinder produce?
Answer: 7,069 lb
Force = Pressure × Area = 1,000 psi × π×(1.5)² ≈ 1,000 × 7.07 ≈ 7,069 lb.