Tech

Question 1

Distinguish between fatigue and creep

Answer 1

Fatigue is reduced tendency of a material to offer resistance to applied stress under repeated or fluctuating loading conditions

Creep is low and progressive deformation of a material with time under constant stress while at high-temperature conditions

Question 2

2nd law of Thermodynamics

Answer 2

Total entropy within a closed system will always increase and never decrease over time

Question 3

What is a process flow diagram

Answer 3

PFD shows the relationship between major equipment or components of a plant facility, leaving out minor details

Question 4

Explain mechanical refrigeration

Answer 4

Using an artificial heat exchange system, mechanical refrigeration is a process where heat is removed from a chosen location. This refrigeration system can be thermoelectric, magnetic, non-cyclic, cyclic, etc.

Question 5

Describe the difference between a tube and a pipe

Answer 5

Pipes are always round while tubes can come in difference shapes and sizes, such as rectangular or square.

For pipes, pressure is evenly distributed due to the circular shape of the pipe.

To measure a tube, outside diameter and wall thickness are used

Question 6

Explain what a bearing is

Answer 6

A bearing is a machine element that constrains relative motion to only the desired motion and reduces friction between moving parts

Question 7

Types of bearings

Answer 7

Ball bearing, Roller, plain, flexible, needle, linear, fluid, magnetic, taper, cylinder

Question 8

P&ID

Answer 8

Piping and instrumentation diagram. This diagram shows process equipment and piping together with control devices and instrumentation in detail

Question 9

GD&T

Answer 9

Geometric dimensioning and tolerance- system for defining and communication engineering tolerances. It provides the maximum amount of tolerance for the part to function properly, which reduces part complexity so that you aren’t overspending for a minimum tolerance that you may not need

Question 10

To increase corrosion resistance of steel, which elements do you need?

Answer 10

Chromium and nickel

Question 11

How does a hydraulic system work

Answer 11

Hydraulic pump pushes the fluid through the system and converts mechanical energy into hydraulic fluid power. Valves control the flow of the liquid and relieve excessive pressure from the system if needed. The hydraulic cylinder converts energy back into mechanical energy

Question 12

What mechanical engineering tasks interest you?

Answer 12

Problem solving (equations, design issues), testing, engineering analysis, building prototypes