In this post, we discussed the top 50 Basic mechanical engineering interview questions and answers in 2023. So if you are a Mechanical Engineer, all these questions and answers are definitely helped you in your upcoming interview.
Basic mechanical engineering interview questions
Following are the top 50 Basic mechanical engineering interview questions :
What is mechanical engineering?
What are the primary areas of application for mechanical engineering?
What are the different types of forces in mechanics?
Explain the concept of stress and strain.
What is the difference between brittle and ductile materials?
Define the term “moment of inertia.”
What is the difference between heat and temperature?
What are the laws of thermodynamics?
Explain the concept of work and power.
What is the difference between static and dynamic equilibrium?
How does a refrigeration cycle work?
What is the difference between a compressor and an expander?
Define the term “governing equation” in mechanical engineering.
What is the significance of the Reynolds number?
What is a heat exchanger, and how does it work?
What are the different types of pumps and their applications?
What is the role of a gearbox in a mechanical system?
How do you calculate the efficiency of a machine?
Explain the concept of fluid viscosity.
What is the difference between laminar and turbulent flow?
How does an internal combustion engine work?
What is the difference between a two-stroke and a four-stroke engine?
Define the term “turbine” and explain its applications.
What is the function of a clutch in a vehicle?
Explain the working principle of a hydraulic system.
What are the safety precautions to be followed while working with heavy machinery?
Describe the working principle of a centrifugal pump.
How does a hydraulic brake system work?
Explain the concept of gear ratio.
What is the difference between a bolt and a screw?
Describe the working principle of a four-bar linkage.
How does a cam and follower mechanism work?
Explain the purpose of a flywheel in a rotating system.
What is the function of a differential in an automobile?
Define the term “tolerance” in manufacturing.
How does a regenerative braking system work?
Explain the concept of fatigue failure in materials.
What is the role of a pressure relief valve?
Describe the working principle of a solenoid valve.
What are the different types of welding processes?
Explain the concept of strain energy.
How does a hydraulic press work?
What is the purpose of a radiator in a vehicle?
Describe the working principle of a scissor lift.
How does a governor system work in a steam turbine?
What is the role of a bearing in a mechanical system?
Explain the working principle of a shock absorber.
What are the different types of gear?
Describe the working principle of a reciprocating compressor.
Basic Mechanical Engineering interview Questions with Answers
So, let’s discuss the Answers to Basic Mechanical Engineering Interview Questions:
1. What is mechanical engineering?
Answer: Mechanical engineering is a branch of engineering that deals with the design, analysis, manufacturing, and maintenance of mechanical systems. It involves the application of principles of physics and materials science to create devices and machines that are used in various industries.
2. What are the primary areas of application for mechanical engineering?
Answer: Mechanical engineering finds applications in various fields such as automotive, aerospace, energy, manufacturing, robotics, HVAC (heating, ventilation, and air conditioning), and biomedical engineering.
3. What are the different types of forces in mechanics?
Answer: The different types of forces in mechanics include tension, compression, shear, bending, torsion, and friction.
4. Explain the concept of stress and strain.
Answer: Stress is the internal resistance of a material to deformation under the application of an external force, while strain is the measure of the deformation experienced by a material relative to its original shape and size.
5. What is the difference between brittle and ductile materials?
Answer: Brittle materials exhibit little to no plastic deformation before failure, while ductile materials can undergo significant plastic deformation before failure.
6. Define the term “moment of inertia.”
Answer: Moment of inertia is a property of a body that describes its resistance to rotational motion around a specific axis. It depends on the mass distribution of the body relative to that axis.
7. What is the difference between heat and temperature?
Answer: Heat is a form of energy transfer, while temperature is a measure of the average kinetic energy of the particles in a substance.
8. What are the laws of thermodynamics?
Answer: The laws of thermodynamics include the first law (conservation of energy), the second law (entropy increase in isolated systems), and the third law (approach to absolute zero temperature).
9. Explain the concept of work and power.
Answer: Work is the product of a force applied to an object and the displacement of that object in the direction of the force. Power is the rate at which work is done, or the amount of work done per unit time.
10. What is the difference between static and dynamic equilibrium?
Answer: Static equilibrium occurs when all forces acting on an object balance each other, resulting in no net force or acceleration. Dynamic equilibrium refers to a system in motion where the net force and net torque are zero.
11. How does a refrigeration cycle work?
Answer: A refrigeration cycle uses the principles of thermodynamics to transfer heat from a low-temperature environment to a high-temperature environment, cooling the low-temperature environment in the process. It typically involves a compressor, condenser, expansion valve, and evaporator.
12. What is the difference between a compressor and an expander?
Answer: A compressor is a device that increases the pressure of a gas, while an expander is a device that decreases the pressure of a gas.
13. Define the term “governing equation” in mechanical engineering.
Answer: A governing equation is a mathematical equation that describes the behavior or relationship between various parameters in a mechanical system. It is derived from fundamental principles or laws of physics.
14. What is the significance of the Reynolds number?
Answer: The Reynolds number is a dimensionless quantity used in fluid mechanics to predict the flow regime (laminar or turbulent) of a fluid. It compares the inertial forces to the viscous forces in the fluid.
15. What is a heat exchanger, and how does it work?
Answer: A heat exchanger is a device used to transfer heat between two fluids at different temperatures, without allowing them to mix. It typically consists of tubes or plates through which the fluids flow, facilitating heat transfer.
16. What are the different types of pumps and their applications?
Answer: Different types of pumps include centrifugal pumps (used in water supply systems, HVAC systems, and process industries), reciprocating pumps (used in high-pressure applications such as hydraulic systems), and rotary pumps (used in lubrication systems and fuel transfer applications).
17. What is the role of a gearbox in a mechanical system?
Answer: A gearbox is used to transmit power and torque from a prime mover (such as an engine or motor) to the driven equipment at a different speed or torque. It provides speed reduction or increase and torque multiplication or reduction as required.
18. How do you calculate the efficiency of a machine?
Answer: The efficiency of a machine is calculated by dividing the useful output or work done by the machine by the total input or energy supplied to the machine, and then multiplying by 100 to express it as a percentage. Efficiency = (Useful output / Total input) * 100.
19. Explain the concept of fluid viscosity.
Answer: Fluid viscosity is a measure of a fluid’s resistance to flow or its internal friction. It determines how easily a fluid can deform under shear stress. Higher viscosity fluids flow more slowly than lower viscosity fluids.
20. What is the difference between laminar and turbulent flow?
Answer: Laminar flow refers to smooth, orderly flow with well-defined layers, while turbulent flow is characterized by irregular fluctuations and mixing of fluid particles. Laminar flow occurs at low velocities or high viscosity, while turbulent flow occurs at high velocities or low viscosity.
21. How does an internal combustion engine work?
Answer: An internal combustion engine converts the chemical energy stored in fuel into mechanical energy. It operates by compressing a fuel-air mixture in a combustion chamber and igniting it, which creates a rapid expansion of gases that drives a piston, producing rotary motion.
22. What is the difference between a two-stroke and a four-stroke engine?
Answer: A two-stroke engine completes a power cycle in two strokes of the piston (one upstroke and one downstroke) and requires a premixed fuel-oil mixture. A four-stroke engine completes a power cycle in four strokes (intake, compression, combustion, and exhaust) and uses separate fuel and lubricating oil systems.
23. Define the term “turbine” and explain its applications.
Answer: A turbine is a device that converts the kinetic energy of a fluid (liquid or gas) into rotational mechanical energy. It is commonly used in power generation systems, such as steam turbines in thermal power plants and gas turbines in aircraft engines.
24. What is the function of a clutch in a vehicle?
Answer: A clutch is used to engage or disengage the power transmission between the engine and the gearbox of a vehicle. It allows the driver to smoothly start, stop, or change gears without damaging the transmission.
25. Explain the working principle of a hydraulic system.
Answer: A hydraulic system uses a fluid (usually oil) to transmit power and control motion. It works on the principle of Pascal’s law, which states that pressure applied to a fluid in a confined space is transmitted equally in all directions. The system consists of a pump, valves, actuators (cylinders or motors), and hydraulic fluid.
26. What are the safety precautions to be followed while working with heavy machinery?
Answer: Safety precautions while working with heavy machinery include wearing appropriate personal protective equipment (PPE), following lockout/tagout procedures, understanding machine-specific safety guidelines, maintaining clear communication, conducting regular inspections and maintenance, and receiving proper training.
27. Describe the working principle of a centrifugal pump.
Answer: A centrifugal pump converts mechanical energy into kinetic energy and then into pressure energy in a fluid. It uses an impeller that rotates at high speed, creating centrifugal force. This force imparts energy to the fluid, causing it to flow and increase in pressure as it moves radially outward. The fluid is then discharged through the pump outlet.
28. How does a hydraulic brake system work?
Answer: In a hydraulic brake system, when the brake pedal is pressed, it actuates a piston in the master cylinder, which pressurizes the brake fluid. This pressurized fluid is then transmitted through brake lines to the brake calipers or wheel cylinders. The fluid applies force to the brake pads or brake shoes, which press against the rotors or drums, creating friction and slowing down or stopping the vehicle.
29. Explain the concept of gear ratio.
Answer: Gear ratio is the ratio of the number of teeth on the driving gear (input gear) to the number of teeth on the driven gear (output gear). It determines the speed and torque relationship between the gears. A gear ratio greater than 1 results in increased torque and decreased speed, while a gear ratio less than 1 results in increased speed and decreased torque.
30. What is the difference between a bolt and a screw?
Answer: In general, a bolt is used with a nut to fasten two or more parts together, while a screw is used to directly fasten an object into a threaded hole or material. Bolts typically have a shank without threads near the head, while screws have threads along their entire length.
31. Describe the working principle of a four-bar linkage.
Answer: A four-bar linkage is a mechanical linkage consisting of four rigid bars connected by pin joints. It is used to transmit motion and force between two points. By varying the lengths and angles of the bars, different types of motion, such as rotation or translation, can be achieved.
32 How does a cam and follower mechanism work?
Answer: In a cam and follower mechanism, a cam is a specially shaped rotating element that imparts reciprocating or oscillating motion to a follower. The follower is in contact with the cam and transfers the motion to another part of the mechanism. The shape of the cam determines the type of motion produced by the follower.
33. Explain the purpose of a flywheel in a rotating system.
Answer: A flywheel is a rotating mechanical device used to store rotational energy. It helps to smooth out variations in speed and torque, acting as a kinetic energy reservoir. In systems with intermittent or fluctuating power sources, such as internal combustion engines, the flywheel provides energy during low power periods and absorbs excess energy during high power periods, maintaining more consistent operation.
34. What is the function of a differential in an automobile?
Answer: The differential is a device used in automobiles to distribute torque or power to the wheels while allowing them to rotate at different speeds, especially during cornering. It helps the wheels to rotate at different speeds while maintaining traction and preventing tire scrubbing or skidding.
35. Define the term “tolerance” in manufacturing.
Answer: Tolerance refers to the allowable variation or deviation from a specified dimension or specification in a manufacturing process. It determines the acceptable limits within which a part or component can deviate from its ideal design dimensions.
36. How does a regenerative braking system work?
Answer: In a regenerative braking system, the kinetic energy of a moving vehicle is converted into electrical energy and stored in a battery or capacitor. When the brakes are applied, the electric motor or generator operates in reverse, acting as a generator and converting the vehicle’s kinetic energy into electrical energy, which is then fed back into the battery for later use.
37. Explain the concept of fatigue failure in materials.
Answer: Fatigue failure occurs when a material undergoes repeated loading and unloading cycles, leading to progressive damage and eventual failure, even if the applied loads are below the material’s ultimate strength. It is caused by the accumulation of microstructural changes and cracks due to cyclic stress.
38. What is the role of a pressure relief valve?
Answer: A pressure relief valve is a safety device used to protect pressure vessels, pipelines, and other systems from excessive pressure. It automatically opens and releases fluid or gas when the pressure exceeds a predetermined set point, preventing damage or failure of the system.
39. Describe the working principle of a solenoid valve.
Answer: A solenoid valve is an electromechanical device used to control the flow of fluids or gases. It consists of a solenoid coil and a movable plunger. When an electrical current is passed through the coil, it creates a magnetic field that attracts the plunger, opening or closing the valve to allow or stop the flow.
40. What are the different types of welding processes?
Answer: Different types of welding processes include arc welding (such as shielded metal arc welding, gas metal arc welding, and gas tungsten arc welding), resistance welding (such as spot welding and seam welding), and laser welding. Each process has its own advantages and applications.
41. Explain the concept of strain energy.
Answer: Strain energy is the energy stored within a material when it undergoes deformation. It is a result of the elastic behavior of the material. When a material is subjected to external forces or loads, it deforms, and the energy required to deform it is stored as strain energy.
42. How does a hydraulic press work?
Answer: A hydraulic press uses a hydraulic system to generate and transmit a large amount of force through a fluid. When a small force is applied to a small piston, it creates pressure in the fluid, which is transmitted to a larger piston. The larger piston experiences a proportionally larger force, allowing the hydraulic press to exert a high force for various applications like metal forming or compression.
43. What is the purpose of a radiator in a vehicle?
Answer: A radiator is a heat exchanger used in vehicles to dissipate heat from the engine coolant. It removes excess heat generated by the engine through a network of tubes and fins, allowing the coolant to cool down before it returns to the engine for further cooling.
44. Describe the working principle of a scissor lift.
Answer: A scissor lift is a type of lifting mechanism that uses a scissor-like arrangement of crossed supports to raise or lower a platform vertically. When the scissor arms are extended, the platform is lifted, and when they are compressed, the platform is lowered. This is achieved by applying a force to the ends of the scissor arms, which causes them to collapse or extend.
45. How does a governor system work in a steam turbine?
Answer: A governor system in a steam turbine controls the speed and output power of the turbine. It consists of a flyball governor, which uses centrifugal force to control the position of a valve that regulates steam flow into the turbine. As the turbine speed changes, the governor adjusts the valve opening to maintain a desired speed and power output.
46. What is the role of a bearing in a mechanical system?
Answer: Bearings are mechanical components that support and facilitate the rotational or linear movement of parts in a mechanical system. They reduce friction between moving parts and provide smooth operation. Bearings come in various types, such as ball bearings, roller bearings, and plain bearings.
47. Explain the working principle of a shock absorber.
Answer: A shock absorber is a device used to dampen and control the vibrations and oscillations of a vehicle’s suspension system. It works on the principle of converting kinetic energy into heat energy. When a vehicle encounters a bump or uneven surface, the shock absorber’s piston moves up and down, compressing hydraulic fluid or gas within the shock absorber. This fluid or gas undergoes resistance, converting the kinetic energy of the suspension movement into heat energy, thus providing a smoother ride.
48. What are the different types of gears?
Answer: Different types of gears include spur gears (straight teeth and parallel shafts), helical gears (angled teeth for smoother engagement), bevel gears (conical teeth for transmitting motion between non-parallel shafts), worm gears (used for high gear reduction ratios), and rack and pinion gears (used for linear motion).
49. Describe the working principle of a reciprocating compressor.
Answer: A reciprocating compressor is a type of positive displacement compressor that compresses gas or air by reciprocating piston motion. As the piston moves downwards, it creates a vacuum that draws in the gas. When the piston moves upwards, it compresses the gas, increasing its pressure. This compressed gas is then discharged through a valve.
50. How does a heat pump function?
Answer: A heat pump is a device that transfers heat from a lower-temperature source to a higher-temperature sink using mechanical work. It operates in a similar manner to a refrigeration cycle, but in reverse. The heat pump uses a compressor to circulate a refrigerant that absorbs heat from the low-temperature source (such as the outside air or the ground) and releases it to the higher-temperature sink (such as the indoor space being heated). It can provide both heating and cooling functions.
51 What is CC in Engines?
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These answers should give you a good foundation for understanding the basic concepts related to mechanical engineering. Remember to study further and delve deeper into each topic to enhance your knowledge and prepare for your interview effectively.