Mechanical Engineering Interview Questions With Answers (Updated 2021)

Mechanical Engineering Interview Questions

Get Latest & Updated Mechanical Engineering Interview Questions with Answers 2021 from here. Getting a Job in well reputed company is a dream of most Mechanical Engineers. You need to stand out from rest of crowd and make best impression in Interview.

However, if you find out, there are always a few set of Mechanical Engineering Interview Questions which are always a part of interview session. Download Mechanical Engineering Interview Questions PDF from here and prepare accordingly.

Mechanical Engineering Interview Questions

Mechanical Engineering Interview Questions With Answers 2021:

Question 1: Explain the second law of thermodynamics.

Answer: The entropy of the universe increases over time and moves towards a maximum value.

Question 2: What kinds of pipes are used for steam lines?


  • Normally galvanized pipes are not used for steam. Mild steel with screwed or welded fittings are the norm.
  • Pressure and temperature are very important factors to be considered in what type of materials to be used.
  • Steam even at low pressures can be extremely dangerous.

Question 3: What is the difference between shear center flexural center of twist and elastic center?


  • The shear center is the centroid of a cross-section. The flexural center is the center of twist, which is the point on a beam that you can add a load without torsion.
  • The elastic center is located at the center of gravity. If the object is homogeneous and symmetrical in both directions of the cross-section then they are all equivalent.

Check More: Interview Questions and Answers

Question 4: What is the difference between projectile motion and a rocket motion?


  • A projectile has no motor/rocket on it, so all of its momentum is given to it as it is launched. An example of a projectile would be pen that you throw across a room.
  • A rocket or missile does have a motor/rocket on it so it can accelerate itself while moving and so resist other forces such as gravity.

Question 5: What is the alloy of tin and lead?


  • A tin and lead alloy is commonly called solder.
  • Usually solder is a wire with a rosin core used for soldering. The rosin core acts as a flux.

Question 6: Explain Otto cycle.


  • Otto cycle can be explained by a pressure volume relationship diagram. It shows the functioning cycle of a four stroke engine.
  • The cycle starts with an intake stroke, closing the intake and moving to the compression stroke, starting of combustion, power stroke, heat exchange stroke where heat is rejected and the exhaust stroke.
  • It was designed by Nicolas Otto, a German engineer.

Question 7: What is gear ratio?

Answer: It is the ratio of the number of revolutions of the pinion gear to one revolution of the idler gear.

Get Best Answer: How to Prepare For an Interview

Question 8: What is ductile-brittle transition temperature?


  • It is the temperature below which the tendency of a material to fracture increases rather than forming.
  • Below this temperature the material loses its ductility. It is also called Nil Ductility Temperature.

Question 9: What are the differences between pneumatics and hydraulics?


  • Working fluid: Pneumatics use air, Hydraulics use Oil
  • Power: Pneumatic power less than hydraulic power
  • Size: P components are smaller than H components
  • Leakage: Leaks in hydraulics cause fluid to be sticking around the components. In pneumatics, air is leaked into the atmosphere.
  • Pneumatics obtain power from an air compressor while hydraulics require a pump
  • Air is compressible, hydraulic oil is not

Question 10: What is isometric drawing?


It is a 3-D drawing used by draftsmen, architects etc

Question 11: Which conducts heat faster steel copper or brass?


  • Copper conducts heat faster than steel or brass. Any material that is good for conducting heat is also good for electricity in most cases.
  • Wood terrible for transferring heat thus is also insulator for electric.

Question 12: What is a Process Flow Diagram?


  • A Process Flow Diagram (or System Flow Diagram) shows the relationships between the major components in the system.
  • It also has basic information concerning the material balance for the process.

Question 13: Where pneumatic system is used?


  • Any system needs redundancy in work needs pneumatics, because the compressor of the pneumatic system has periodical operations (intermittent work, not as hydraulic pump).
  • The compressed air could be accumulated in tanks with high pressures and used even if the compressor failed.

Do You Know: Interview Tips For Freshers

Question 14: What is representative elementary volume?

Answer:  Smallest volume over which measurements can be made that will yield a representative of the whole.

Question 15: Why are LNG pipes curved?

Answer:  LNG pipes are curved because LNG is condensed gas (-164 deg cel) so it can expand the pipes that is what engineers designed the LNG pipes are curve type.

Question 16: What causes white smoke in two stroke locomotive engines?

Answer:  That is the engine running too lean (lack of fuel). This condition will lead to overheating and failure of the engine.

Question 17: What does Green field project mean?


  • Green field projects are those projects, which do not create any environmental nuisance (pollution), follows environmental management system and EIA (environment impact assessment).
  • These projects are usually of big magnitude.

Question 18: What is the mechanical advantage of a double pulley?

Answer: It only takes half the effort to move an object but twice the distance.

Question 19: What is a Newtonian fluid?


  • A Newtonian fluid possesses a linear stress strain relationship curve and it passes through the origin.
  • The fluid properties of a Newtonian fluid do not change when any force acts upon it.

Question 20: What are the points in the stress strain curve for steel?

Answer:  Proportional limit, elastic limit or yield point, ultimate stress and stress at failure.

Read Also: Best Interview Tips

Question 21: What should be done to prevent a safety valve to stick to its seat ?

Answer: Safety valve should be blown off periodically so that no corrosion can take place on valve and valve seat.

Question 22: Why large boilers are water tube type ?

Answer: Water tube boilers raise steam fast because of large heat transfer area and positive water circulation. Thus they respond faster to fluctuations in demand. Further single tube failure does not lead to catastrophy.

Question 23: What type of boiler does not need a steam drum ?

Answer: Super-critical pressure boiler.

Question 24: Why manholes in vessels are usually elliptical in shape ?

Answer: Elliptical shape has minimum area of opening and thus plate is weakened the least. Further it is very convenient to insert and take out the cover plate from elliptical opening.

Question 25:  Low water in boiler drum is unsafe because it may result in overheating of water tubes in furnace. Why it is unsafe to have high water condition in boiler drum ?

Answer: High drum level does not allow steam separation to be effective and some water can be carried over with steam which is not desirable for steam turbine.

What is the work of Mechanical Engineer?

All the Mechanical engineers examine, design, develop, build, and also test a mechanical as well thermal device that includes tools, engines, and machines. Generally, Mechanical engineers do the work which is given below here.

  • To analyze the problem, how can mechanical and thermal devices help to solve the problem
  • They Design or redesign mechanical as well as thermal devices by using analysis and computer-aided design.
  • Mechanical Engineer develops and test prototypes of devices they design.
  • They also examine the test results and can change the design if required.
  • Supervise the industrialized process for the device.

Know More: Highest Paying Government Jobs in India

Top Companies Employing Mechanical Engineers

If you possess degree or diploma in mechanical engineering, you can easily find job in various government as well as private sector companies. Several government sector companies that employ mechanical engineers are as follows. You can also check Mechanical Engineering Salary In India from here

Mechanical Engineering Interview Questions and Answer 2021:

Get Mechanical Engineering Interview Questions 2021 And Answers from here. We hope, you are satisfied with the info given by the team members of regarding Mechanical Engineering Interview Questions 2021.

If, you have any doubt related to Mechanical Engineering Interview Questions & Answers PDF, then you are free to ask it in below given comment box. Our expert team will definitely solve your query about mechanical engineering interview questions PDF.

Candidates, who effectively reach final stage and don’t want to lose this opportunity, can start their preparation for interview round with help of Mechanical Engineering Interview Questions provided above.

Something That You Should Put An Eye On

Top Universities in IndiaScholarship in India
UGC Approved University ListBest Career Opportunities
Top Colleges in IndiaCollege is Registered OR AICTE
List of Fake UniversitiesHow Do Toppers Study?

Filed in: Interview

Leave a Reply

Submit Comment