WTMA Hydraulics and Fluid Dynamics 3

Question 1

A hydraulic cylinder has a bore of 3 inches and operates at 1,000 psi. Approximately what push force can it generate? (Force = Pressure × Area)

Accepted Answer

7,069 lbs

Answer

Area = π × (1.5)² ≈ 7.07 sq in; Force = 1,000 × 7.07 ≈ 7,069 lbs.

Question 2

Which type of pump is most commonly used in hydraulic systems to move fluid?

Accepted Answer

Positive displacement pump

Answer

Positive displacement pumps deliver a fixed volume per cycle, making them ideal for high-pressure hydraulic systems.

Question 3

If a hydraulic fluid reservoir runs low, what is the most likely immediate consequence?

Accepted Answer

Pump cavitation and potential pump damage

Answer

Low fluid causes the pump to draw in air, leading to cavitation which damages pump components.

Question 4

A directional control valve in a hydraulic system is used to:

Accepted Answer

Control which way a cylinder extends or retracts

Answer

Directional control valves route fluid to one side of a cylinder or the other to control direction of motion.

Question 5

Hydraulic fluid must be incompressible for the system to work properly. Why?

Accepted Answer

So force is transmitted instantly without energy loss to compression

Answer

Incompressible fluid transmits force directly; a compressible fluid would absorb energy before moving the load.

WTMA - Wiesen Test of Mechanical Aptitude Practice Test