Mechanical Aptitude Hydraulics and Pneumatics Questions and Answers 2

Question 1

What is the main difference between hydraulic and pneumatic systems?

Accepted Answer

Hydraulic systems use liquid, pneumatic use gas

Answer

Hydraulic systems use incompressible liquids (typically oil) to transmit force, while pneumatic systems use compressible gases (typically air). This fundamental difference gives hydraulics greater force capability and precision.

Question 2

In a hydraulic system, if the input piston has an area of 2 cm² and the output piston has an area of 20 cm², what is the force multiplication factor?

Accepted Answer

10

Answer

The force multiplication equals the ratio of output piston area to input piston area: 20 cm² / 2 cm² = 10. A force of 100N on the input piston produces 1000N at the output piston.

Question 3

What component in a hydraulic system converts fluid pressure into linear mechanical motion?

Accepted Answer

Hydraulic cylinder

Answer

A hydraulic cylinder (also called a hydraulic actuator or ram) converts hydraulic pressure into linear force and motion. The pump generates the pressure, valves control direction, and the cylinder does the mechanical work.

Question 4

What is the purpose of an accumulator in a hydraulic system?

Accepted Answer

To store pressurized fluid for later use

Answer

An accumulator stores hydraulic fluid under pressure, acting as an energy reserve. It can supplement pump flow during peak demands, absorb pressure shocks, and maintain pressure when the pump is off.

Question 5

Why is air typically dried before being used in a pneumatic system?

Accepted Answer

To prevent corrosion and freezing in the system

Answer

Compressed air contains moisture that can cause corrosion of metal components, freezing in cold conditions (blocking valves and lines), and degradation of lubricants. Air dryers remove this moisture to protect the system.

Mechanical Aptitude Test Practice Test

Mechanical Aptitude Test Practice Test

Mechanical Aptitude Hydraulics and Pneumatics Questions and Answers 2