Technical Questions Asked with Mechanical Engineer in an Interview

Explain how hydraulics work on a machine

Using an incompressible fluid machine use hydraulics to transmit force from one point to another. In most cases, this increases the force applied at one end for a given amount of effort.

What is a process flow diagram?

Commonly used in chemical and process engineering. A process flow diagram (PFD) is a diagram that is used to indicate the general flow of equipment and plant processes. The PFD displays the relationship between major equipment of a plant facility and but doesn’t minor details such as designations and piping details.

What is the difference between a strut and a column? 

A Column is always vertical but a strut could carry an axial compressive load in any direction. A strut and column both carry the compressive load.

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

Chromium and nickel.

What are the principal constituents of brass?

Copper and since are the principal constituents of brass are copper.

An elastomer is a polymer when its percentage elongation rate is?

Greater than 100%.

Distinguish between fatigue and creep.

Fatigue is the 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 at high-temperature applications.

What is the second law of thermodynamics?

The second law of thermodynamics states that total entropy will always increase within a closed system and can never decrease over time.

What is the process flow diagram? 

A process flow diagram is a diagram commonly used in chemical and process engineering to indicate the general flow of plant processes and equipment.

Explain mechanical refrigeration

Using an artificial heat exchange system mechanical refrigeration is a process where heated is removed from a chosen location. This refrigeration system can be thermoelectric, magnetic, non-cyclic, cyclic, and will depend on the refrigeration application needed.

Describe the difference between a tube and a pipe

Pipes are always round while tubes can come in different shapes such as rectangular, square, or cylindrical. A pressure force is evenly distributed due to the circular shape of a pipe. Outside diameter (OD) and wall thickness (WT) are used to measure a tube.

Explain what a bearing is?

Bearings precision-made components that enable machinery to move at high speeds while reducing friction between moving parts.

What is a P&ID? 

Used in the process industry a P&ID is a piping and instrumentation diagram. This diagram shows process equipment and piping together with control devices and instrumentation in detail.

Explain what GD&T is

GD&T stands for geometric dimensioning and tolerancing which is a system for defining and communicating engineering tolerances.