Top 37+ Mechanical Engineering Interview Questions and Answers

Mechanical Engineering is one of the core branches that plays a crucial role in industries ranging from automotive and aerospace to manufacturing and energy sectors. As the demand for skilled mechanical engineers is growing, acing the Mechanical Engineering interview becomes crucial to get your dream job. Whether you are a fresh graduate or an experienced professional, preparing for common Mechanical Engineering interview questions can set you apart from the competition. In this article, we have compiled the Top Mechanical Engineering Interview Questions and Answers that will help you get ready for your next big opportunity.

With the increasing demand for Mechanical Engineers, several institutes are offering mechanical engineering online courses to meet the market demand. One can pursue a mechanical engineering job with comprehensive qualifications and skills in this field. Having an understanding of the type of mechanical engineering interview questions and answers will help you ace the job. You can enrol in online courses & certifications from top providers to learn basic mechanical engineering questions and answers.

Mechanical Engineering: Overview

Basic Mechanical Engineering Interview Questions For Freshers

Here are some of the top basic mechanical engineering interview questions that candidates can refer:

Q1. How do we differentiate thermodynamics and heat transfer?
Ans: To answer this question, you should focus on the basics of these two terms and then describe them. You can say that thermodynamics, which is a crucial branch of physics, works on equilibrium states and alters one equilibrium state to another. Heat transfer, on the other hand, is a non-equilibrium process as it deals with systems that are not in thermal equilibrium.

Q2. Why are most of the gas containers cylindrical in shape?
Ans: Gas containers are made mostly cylindrical to resist high pressure. The sphere ideally is the most efficient shape that resists high internal gas pressure but manufacturing that shape is quite expensive. Conversely, a cylinder with a domed top and bottom is cheaper and has sufficient potential to remain unaffected by the internal gas pressure.

Q3. Explain the role of Nitrogen in welding
Ans: Nitrogen in welding is used to prevent porosity. It stops oxygen and air from entering the fused metal while welding.

Q4. Which gases can be used in place of nitrogen in welding?
Ans: During welding, Argon, Helium, or Carbon Dioxide can be used in place of Nitrogen to prevent porosity.

Q5. What is a periscope? Give its real-life application.
Ans: Periscope typically refers to an optical instrument used for viewing objects which are above the level of sight. In the real world, a periscope is used in submarines to keep an eye on enemies or any other danger.

Q6. What is the reason for white smoke in two-stroke locomotive engines?
Ans: White smoke in two-stroke locomotive engines happens when the engine is running out of fuel. This condition is harmful to the engine as it may result in overheating and, eventually, its failure.

Q7. Can motor oil be used in a hydraulic system?
Ans: Motor oil can be used in a hydraulic system, but we should avoid using it. This is mainly because motor oil has lower sulfur content and contains tackifiers and other elements that are detrimental to seals and other hydraulic system components. Instead, we should use hydraulic fluids.

Q8. Why do airplanes made of thicker paper fly farther?
Ans: This happens because the thicker the paper, the greater its mass and potential energy. Potential energy converts into kinetic energy while moving and this large kinetic energy provides a larger lift to the airplane, and a larger lift results in a large flight distance.

Q9. Explain the difference between the turbine and the pump.
Ans: While the turbine conveys the flow energy of the fluid to mechanical energy, the pump deals with transferring mechanical energy to the fluid.

Q10. Is there any mechanical advantage to using a double pulley?
Ans: Yes, a double pulley cuts our efforts, taking half the effort and moving the object twice the distance.

Q11. What is a Turboprop engine?
Ans: A Turboprop engine refers to a gas turbine engine that powers the propellers. It changes most of its thrust into rotational energy to power a propeller, making it more reliable and efficient for aircraft designs.

Q12. Name the different types of gate valves.
Ans: There are many types of gate valves, namely parallel disk gate valves, Single disk gate valves, and wedge gate valves.

Q13. Are the pneumatic system and the hydraulic system similar? Explain how?
Ans: Yes, both systems are similar in their mode of action. Both the pneumatic system and the hydraulic system use pressure to act on a particular application. As the pneumatic system makes use of gases like air or nitrogen, the hydraulic system uses oil or water.

Q14. Can we see the pipes behind the wall?
Ans: Yes, we can do this by using radio waves.

Q15. Explain the difference between a rocket motion and a projectile motion.
Ans: A rocket motion has a rocket on it, so it can accelerate its motion and resist forces like gravity. On the other hand, a projectile motion has no rocket on it. Thus, all of its momenta are given to the body when it gets launched. Throwing a piece of chalk across a room can be taken as an example of projectile motion.

Q16. Does stress produce strain, or does strain produce stress?
Ans: It is a force that produces both of them. Strain is the measurement of the displacement of an object caused due to applied force whereas stress is the force per unit area. Hence, both are produced by the applied force.

Interview Questions for Mechanical Engineer - Experienced

Q17. What is an Orthographic drawing?
Ans: This is another one of the top mechanical engineering questions and answers that should be included in your mechanical engineer interview questions list. You can answer this question by saying it is a 3D representation of any object. These drawings are made so that if the page is folded accordingly, it would create three faces of the shape. The three faces include its plan view, front view, and side view.

Q18. What is FOF in piping design?
Ans: FOF stands for Face of Flange. It is used to determine the exact dimensions of the flange to avoid errors in measurement in the case of a vertical or horizontal pipeline.

Q19. What is extrusion?
Ans: The term Extrusion is defined as the process of elongating a metal bar by pulling it through a mandrel. This process gives shape to the metal bar. You can learn more about extrusion through mechanical engineering certification courses.

Q20. Give some examples of mechanisms in daily life.
Ans: Some common examples of mechanisms are a light switch and the working of a clock.

Q21. What are Newtonian fluids?
Ans: Fluids that possess a linear stress-strain relationship curve and pass through the origin are called Newtonian fluids. Such fluids do not change due to the action of forces upon them. You can learn more about this by enrolling in mechanical engineering courses.

Q22. What are the two conditions of perfect gas?
Ans: A perfect gas should satisfy the equation of state. The specific heat of the gas should remain constant.

Q23. Why are galvanised pipes not used for steam lines?
Ans: This is one of the top mechanical interview questions. Galvanised pipes are not used for steam lines because the high temperature and pressure of the steam tend to flake off the zinc coating on the pipe. The flaked coating may clog the orifices in the event, leading to an explosion.

Q24. Why is tolerance analysis important for engineers?
Ans: Analysing tolerances helps engineers to reduce costs, avoid time-consuming iterations, and facilitate manufacturing. Every engineer optimises tolerance as it determines how reliable the final piece will be. You can learn mechanical engineering interview questions and answers for freshers by enrolling in mechanical engineering courses.

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Q25. What is mechanical refrigeration?
Ans: A Mechanical Refrigerator is a process in which heat is removed from a particular location using an artificial heat-exchange system. Depending upon its application, refrigeration can be magnetic, cyclic, non-cyclic, or thermoelectric.

Q26. Why is the pneumatic system preferred over the hydraulic system?
Ans: It is so because pneumatic systems are cheaper than hydraulic systems. Additionally, pneumatics move faster and do not leak oil in case of any leakage.

Q27. What is the basic difference between a pipe and a tube?
Ans: A pipe is measured based on its internal diameter, whereas a tube is measured based on its external diameter.

Q28. Give one drawback of supercritical boilers.
Ans: Supercritical boilers lack a heavy drum for the separation of steam from the mixture of water and steam.

Q29. How can you differentiate between cast iron, mild steel, and high-carbon steel?
Ans: These three metals can be differentiated by the kind of spark they produce. Cast iron produces very thick and short flashes. Mild steel produces medium-sized dense sparks, while high carbon steel gives thick, long sparks.

Q30. What are the major and minor head losses in a fluid flow system?
Ans: In the fluid flow system, the losses that occur in the pipes are termed major losses, whereas head losses that occur due to bends and additional parts in the straight pipe system are termed minor losses.

Q31. Name the different types of compressors used in a gas turbine.
Ans: Three types of compressors are used in a gas turbine: Axial compressor, Centrifugal compressor, and Mixed Flow compressor.

Q32. Explain a process flow diagram.
Ans: A process flow diagram is a sketch to describe the primary flow course. It has symbols to identify vessels and other instruments. The illustration shows major equipment, plant streams, key central loops, and a general relationship between components used to complete a task.

Q33. What is the difference between total moisture and the inherent moisture of coal?
Ans: The total moisture of the coal means the total moisture of the sample, while the air-dried sample is known as the inherent moisture of the coal.

Q34. Why is a thermostat used in the cooling system of engines?
Ans: A thermostat in the cooling system works to keep the engine cool at the optimum level. Doing so prevents a decrease in the efficiency of the system.

Mechanical Engineering Technical Interview Questions

Q35. What is a universal coupling?
Ans: Universal coupling is a pair of hinges connected by a cross shaft that connects two shafts with axes inclined to each other. For example, the drive shaft in a car connects to the rear axle via a universal coupling.

Q36. Which one has greater efficiency- A diesel engine or a petrol engine with the same compression ratio?
Ans: With this one of the basic mechanical interview questions, the interviewer tests your knowledge and ability how you make an analysis. The compression ratio is the same, and the petrol engine has greater efficiency than the former one. This is because the Otto cycle rejects less heat than the diesel engine cycle. This is one of the best mechanical engineering fresher interview questions

Q37. What is the Otto cycle?
Ans: Otto cycle is an ideal thermodynamic combustion cycle that describes how heat engines turn gasoline into motion. This cycle works by converting chemical energy into thermal energy and then changing it into motion.

38. What are the different types of cooling towers?
Ans: There are two types of cooling towers - Natural draft and Mechanical/ forced or induced draft.

Q39. Describe the superheating process.
Ans: In the process of superheating, the temperature of the fluid is increased along with its pressure.

Q40. What type of computer programs a mechanical engineer can use in his/her work?
Ans: Mechanical engineers can use various tools and software like Mathcad, MATLAB, SolidWorks, Autodesk Inventor, and Finite Element Analysis (FEA).

Q41. What are the different types of brakes?
Ans: There are various types of brakes related to mechanical engineering, like electric brakes, hydraulic brakes, and mechanical brakes.

Q42. What do you mean by engineering drawing?
Ans: An engineering drawing is nothing but a technical document that is used for transferring technical details by defining requirements. This is used to communicate design ideas and technical information to professionals and engineers throughout the design process.

Q43. What is the significance of clearance in engineering drawings?
Ans: Clearance in engineering drawing ensures that different parts fit together correctly. This is extremely critical for maintaining the precision and assembly in manufacturing.

Q44. What is a Nuclear Reactor?
Ans: A Nuclear Reactor is nothing but a plant protecting against radioactive creation that starts, sustains, controls, and maintains the chain reaction associated with nuclear fission.

Q46. Explain the difference between the total and inherent moisture of coal.
Ans: The total moisture in coal is the bulk moisture sample which gets evaporated easily, whereas inherent moisture is held within the coal known as inherent moisture, and is quantitatively analysed.

Q47. What contribution does Finite Element Analysis (FEA) have in the design process of mechanical engineering?
Ans: Finite Element Analysis (FEA) allows mechanical engineers to validate and optimise mechanical engineering designs. It helps in stress prediction and aids the engineers in looking into their designs and tweaking them if necessary before their physical prototypes are created.

Q48. What are the basic principles of thermoelectric power generation?
Ans: Thermoelectric power generation finds different applications in waste heat recovery and also locating portable power sources. It utilises the feedback effect thereby converting the temperature in between the two materials of an electric voltage.

Q49. What is a uniformly distributed load?
Ans: A uniform load is spread over a beam region where the load magnitude is similar throughout the entire element.

Q50. What is the importance of tolerance analysis for engineers?
Ans: Tolerance analysis is important for mechanical engineers since it helps minimise costs and structure the manufacturing process ultimately helping in guaranteeing the final product's reliability.

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Scope of Mechanical Engineering

Mechanical engineers play a vital role in industries like automotive, robotics, energy, and aerospace. Their job responsibilities include designing mechanical systems, improving manufacturing processes, and ensuring product quality. With experience, professionals can move into managerial roles or specialise in emerging fields like mechatronics and renewable energy.

Mechanical Engineering Scope: Career Growth and Salary Trends

(Source: AmbitionBox)

Skills Needed for Mechanical Engineering

• Technical Skills: CAD/CAM, Thermodynamics, Fluid Mechanics
• Soft Skills: Problem-solving, Teamwork, Communication
• Emerging Skills: Robotics, AI in Manufacturing, Sustainable Design

Apart from these mechanical engineering fresher interview questions, the interviewer may ask some problem-solving questions. So, you need to prepare yourself by understanding different problems and addressing them holistically. You can ace all types of mechanical engineering interview questions and prepare answers if you have good knowledge. Candidates can be a step closer to securing their dream job if they master the above-mentioned interview questions on mechanical engineering. These questions will help them understand the basic principles, concepts, and processes in mechanical engineering.