800+ Mechanical Engineer Interview Questions and Answers

Diesel engines are commonly used in trains.

• Trains typically use diesel engines due to their high torque and fuel efficiency.

• Electric engines are also used in some trains, especially in urban areas.

• Steam engines were used in the past but are now rare.

• Hybrid engines that combine diesel and electric power are becoming more common.

• The type of engine used in a train depends on factors such as the distance it travels and the terrain it covers.

Sewage treatment plants involve chemical, mechanical, and electrical processes.

• Chemical processes involve the use of chemicals to remove contaminants from the sewage.

• Mechanical processes involve physical methods like screening, sedimentation, and filtration to remove solids and other impurities.

• Electrical processes involve the use of electrical equipment like pumps and motors to move sewage through the treatment plant.

• Examples of processes include activated sludge process, tr...read more

I regularly use programming languages like Python, MATLAB, and C++ in my work as a Mechanical Engineer.

• Python, MATLAB, and C++ are the programming languages I use regularly.

• I have experience in writing code for data analysis, simulation, and control systems.

• For example, I have used Python to develop algorithms for analyzing experimental data and MATLAB for modeling and simulating mechanical systems.

• I also have experience in using C++ for developing software for embedded syste...read more

Manpower can be managed by proper planning, delegation of tasks, and effective communication.

• Create a detailed project plan with timelines and milestones

• Delegate tasks based on individual strengths and expertise

• Ensure effective communication channels are established

• Regularly monitor progress and make necessary adjustments

• Utilize helpful mechanical sources such as automation and technology

• Provide necessary training and resources to team members

• Encourage teamwork and collaborat...read more

Tolerance is the allowable variation in a dimension or measurement.

• Tolerance is important in engineering to ensure that parts fit together properly and function as intended.

• It is usually expressed as a range of acceptable values, such as +/- 0.1mm.

• Tolerance can be affected by factors such as manufacturing processes, materials, and design requirements.

• Tolerance can also be used to control the fit and clearance between mating parts, such as in bearings or gears.

• Tolerance analys...read more

A lathe machine is used to shape metal or wood by rotating it against a cutting tool. A milling machine is used to cut and shape solid materials.

• Lathe machine rotates the workpiece while the cutting tool remains stationary

• Milling machine uses a rotating cutting tool to remove material from a stationary workpiece

• Lathe machine is used for turning, drilling, facing, and threading operations

• Milling machine is used for cutting, drilling, and shaping solid materials

• Examples of lath...read more

Pump and compressor are both fluid handling devices, but pump moves liquid while compressor moves gas. Types of heat exchangers are shell and tube, plate and frame, and finned tube. Package equipment is a pre-engineered set of components for a specific application.

• Pump moves liquid while compressor moves gas

• Pump increases the pressure of liquid while compressor increases the pressure of gas

• Types of heat exchangers include shell and tube, plate and frame, and finned tube

• Packag...read more

The firing order of a 6-cylinder engine is different from that of a 4-cylinder engine.

• The firing order determines the sequence in which the cylinders ignite their fuel-air mixture.

• In a 6-cylinder engine, the firing order can vary depending on the engine design.

• A common firing order for a 6-cylinder engine is 1-5-3-6-2-4.

• In a 4-cylinder engine, the firing order is typically 1-3-4-2.

Types of fits include clearance fit, interference fit, and transition fit.

• Clearance fit: parts are intended to have a gap between them

• Interference fit: parts are intended to be pressed or forced together

• Transition fit: parts have a combination of clearance and interference fit

• ISI system divides fits into these three categories

• Fits are important in ensuring proper functioning of mechanical systems

Engineers need to know the benefits and scopes of technical know-how.

• Technical know-how helps engineers to design and develop innovative products.

• It enables engineers to troubleshoot and solve complex problems.

• Technical know-how helps engineers to stay updated with the latest technologies and trends.

• It helps engineers to communicate effectively with other technical professionals.

• Technical know-how also helps engineers to improve their career prospects and job opportunities.

There are two types of brakes used in mining dumpers: service brakes and parking brakes.

• Service brakes are used to slow down or stop the dumper while it is in motion.

• Parking brakes are used to hold the dumper in place when it is parked or stationary.

• Examples of service brakes include hydraulic brakes and air brakes.

• Examples of parking brakes include hand brakes and spring brakes.

Indian standards are guidelines set by Bureau of Indian Standards (BIS) to ensure quality, safety, and reliability in various industries.

• Indian standards are set by the Bureau of Indian Standards (BIS) to ensure quality, safety, and reliability in various industries.

• Following Indian standards helps in maintaining uniformity, interoperability, and compatibility in products and services.

• Deviation from Indian standards may lead to issues such as safety hazards, poor quality, and...read more

The number of engineering documents processed in an EPC project depends on the project scope and complexity.

• The number of engineering documents can range from a few hundred to several thousand.

• Documents include design drawings, specifications, calculations, reports, and contracts.

• The project size, type, and location can also impact the number of documents.

• Efficient document management is crucial for project success and timely completion.

• Examples of EPC projects include power ...read more

Increasing casting pressure and second phase velocity can improve casting quality and reduce defects.

• Higher casting pressure can help fill the mold more completely and reduce porosity.

• Increased second phase velocity can improve the distribution of the second phase material in the casting.

• However, increasing both too much can lead to other defects like shrinkage or cracking.

• Optimizing these parameters requires careful consideration of the specific casting process and materials...read more

Low width of coil can affect performance, increasing it can improve efficiency.

• Low coil width can lead to poor heat transfer and reduced efficiency

• Increasing coil width can improve heat transfer and increase efficiency

• Factors such as space constraints and cost may limit the ability to increase coil width

PCI equipment maintenance involves regular inspections, cleaning, and repairs to ensure optimal performance and safety.

• Create a maintenance schedule based on manufacturer recommendations and usage frequency

• Perform regular inspections to identify any signs of wear or damage

• Clean equipment regularly to prevent buildup of debris or contaminants

• Perform repairs as needed to address any issues or malfunctions

• Document all maintenance activities for future reference and tracking

• Train...read more

The power of a pump can be calculated using the formula: Power = (Flow rate x Head) / Efficiency

• The power of a pump is determined by the flow rate, head, and efficiency

• Flow rate is the volume of fluid passing through the pump per unit time

• Head is the height difference between the inlet and outlet of the pump

• Efficiency is the ratio of the actual power output to the power input

• The formula to calculate power is: Power = (Flow rate x Head) / Efficiency

• For example, if the flow rat...read more

Gears are mechanical components that transmit power and motion between rotating shafts. There are various types of gears.

• Spur gears are the most common type and have straight teeth.

• Helical gears have angled teeth and provide smoother operation.

• Bevel gears transmit power between shafts that are not parallel.

• Worm gears have a screw-like thread and are used for high reduction ratios.

• Planetary gears have a central gear that rotates around other gears.

• Rack and pinion gears convert...read more

A 4 stroke engine is an internal combustion engine that completes 4 strokes in one cycle.

• The four strokes are intake, compression, combustion, and exhaust.

• In the intake stroke, the fuel-air mixture is drawn into the cylinder.

• In the compression stroke, the mixture is compressed to increase its temperature and pressure.

• In the combustion stroke, the mixture is ignited and the resulting explosion pushes the piston down.

• In the exhaust stroke, the spent gases are expelled from the ...read more

I would assess the impact of the out-of-tolerance part and determine if it can still function within acceptable limits or if it needs to be reworked or replaced.

• Assess the functionality of the part with the out-of-tolerance dimensions

• Determine if the part can still meet the overall design requirements despite being out of tolerance

• Consider the potential impact on the performance and safety of the final product

• Consult with the design team to evaluate if adjustments can be made...read more

Measurements in micrometers are used for very small distances.

• Micrometers are commonly used in precision engineering and manufacturing.

• 1 micrometer is equal to 0.001 millimeters.

• Examples of measurements in micrometers include the thickness of a human hair (around 70 micrometers) and the width of a red blood cell (around 8 micrometers).

Actual stress is the force applied to a material, while engineering stress is the force per unit area of the original cross-sectional area.

• Actual stress is calculated using the actual area of the material that is being stressed, while engineering stress is calculated using the original cross-sectional area of the material.

• Engineering stress is commonly used in engineering design and analysis, while actual stress is used in material testing and failure analysis.

• For example, if...read more

Engine oil pressure is the pressure at which the oil is pumped through the engine to lubricate its moving parts.

• Engine oil pressure is measured in pounds per square inch (PSI).

• Low oil pressure can cause engine damage and should be addressed immediately.

• Oil pressure can vary depending on engine speed and temperature.

• Oil pressure gauges are typically located on the dashboard of a vehicle.

• Normal oil pressure for most engines is between 20 and 60 PSI.

Belt conveyors maintenance involves regular inspection, cleaning, and lubrication.

• Inspect belts for wear and tear

• Clean belts and rollers to prevent buildup of debris

• Lubricate bearings and other moving parts

• Tighten loose bolts and replace damaged parts

• Train employees on proper use and maintenance procedures

Checkpoints during installation of reactor mechanical seal

• Alignment of seal faces

• Proper installation of seal support system

• Correct torque applied to bolts

• Verification of seal flush system

• Inspection of seal faces for damage or defects

• Testing of seal for leakage

• Documentation of installation process

Manufacturing processes include casting, forging, machining, welding, and more.

• Casting: pouring molten metal into a mold to create a solid object

• Forging: shaping metal by heating and hammering

• Machining: using tools to remove material from a workpiece

• Welding: joining two pieces of metal by melting them together

• Additive manufacturing: building up layers of material to create a 3D object

• Forming: shaping metal without removing material, such as bending or stamping

• Extrusion: forci...read more

Thermodynamics is the study of energy and its transformations in relation to heat and work.

• It deals with the behavior of energy and its conversion from one form to another.

• It involves the study of heat transfer, work, and the properties of substances.

• Thermodynamics is essential in designing and analyzing various mechanical systems.

• Examples include the study of engines, refrigeration systems, and power plants.

Hydraulics is a branch of engineering that deals with the mechanical properties of liquids, especially water or oil, and their applications.

• Hydraulics involves the study of fluid mechanics and the behavior of liquids under pressure.

• It is used in various applications such as hydraulic machinery, hydraulic systems, and hydraulic power transmission.

• Hydraulic systems use fluid pressure to generate, control, and transmit power.

• Examples of hydraulic systems include hydraulic lifts,...read more

Material handling process using belt conveyor system involves transporting materials efficiently. The width and type of belt conveyor depend on the specific application.

• Belt conveyor system is used to transport materials from one location to another in a production facility or warehouse.

• The width of the belt conveyor depends on the size and weight of the materials being transported. It can range from a few inches to several feet.

• The type of belt conveyor can vary based on the...read more

Total Productive Maintenance (TPM) is a maintenance strategy that aims to maximize equipment effectiveness and minimize downtime.

• TPM involves the entire workforce in the maintenance process

• It focuses on proactive maintenance to prevent breakdowns

• TPM has eight pillars including autonomous maintenance, planned maintenance, and quality maintenance

• TPM aims to improve overall equipment effectiveness (OEE) by reducing downtime, improving quality, and increasing productivity

Maintenance philosophies include preventive, predictive, corrective, and reliability-centered maintenance.

• Preventive maintenance involves regularly scheduled inspections and maintenance to prevent equipment failure.

• Predictive maintenance uses data analysis and monitoring to predict when maintenance is needed.

• Corrective maintenance is performed after a failure has occurred to restore equipment to working condition.

• Reliability-centered maintenance focuses on identifying critica...read more

Belt joint process involves connecting two ends of a belt. Belt width and type depend on the application.

• Belt joint process includes mechanical fasteners, vulcanization, and welding.

• Belt width depends on the conveyor system's design and the material being transported.

• Types of belts include flat belts, V-belts, timing belts, and ribbed belts.

• Belt type depends on the application, load capacity, speed, and environment.

• Common materials for belts include rubber, PVC, nylon, and po...read more

Blade efficiency of impulse turbine is typically around 80-90%.

• Blade efficiency is a measure of how effectively the blades of a turbine convert the kinetic energy of the fluid into mechanical energy.

• It is calculated as the ratio of the actual work done by the blades to the work that would be done if the fluid were to expand isentropically.

• Blade efficiency for impulse turbines is generally higher than reaction turbines, typically ranging from 80-90%.

• Factors affecting blade eff...read more

The efficiency of an impulse turbine is typically around 70-90%.

• Efficiency is calculated as the ratio of actual work output to the theoretical work input.

• Impulse turbines have high efficiency due to the fact that the energy transfer occurs in stages.

• Efficiency can be affected by factors such as blade design, operating conditions, and maintenance.

• Examples of impulse turbines include Pelton wheel and Turgo turbine.

The obsolete angle of impulse turbine is the angle at which the blades are set in relation to the direction of the water flow.

• Obsolete angle is typically around 20-22 degrees for impulse turbines.

• It determines the efficiency and performance of the turbine.

• Incorrect angle can lead to reduced power output and efficiency.

• Examples: Pelton wheel, Turgo turbine.

In a 4 point bending test, the stresses and moments are described, along with the failure and fracture behavior.

• In a 4 point bending test, a beam is subjected to bending forces at two points and supported at two other points.

• The stresses in the beam are highest at the top and bottom surfaces, resulting in tension and compression.

• The moments in the beam are highest at the points of loading and decrease towards the supports.

• At fracture, the beam fails due to excessive tensile s...read more

The density of water is approximately 1 gram per cubic centimeter.

• The density of water is a fundamental property of the substance.

• It is commonly used as a reference point for comparing the densities of other substances.

• The density of water varies slightly with temperature and pressure.

• At 4 degrees Celsius, the density of water is exactly 1 gram per cubic centimeter.

• Water is less dense in its solid form (ice) than in its liquid form.

Resources and manpower can be handled efficiently by proper planning and allocation.

• Identify the required resources and manpower for the project

• Allocate resources and manpower based on their skills and availability

• Regularly monitor the progress and adjust the allocation if necessary

• Maintain open communication with the team to ensure smooth workflow

• Implement contingency plans in case of unexpected events

Change in class in duct pressurization affects ducting installation and fabrication.

• A change in class may require different materials for ducting installation and fabrication.

• Higher class ducts may require thicker materials to withstand higher pressures.

• Lower class ducts may require less expensive materials to meet pressure requirements.

• Changes in class may also affect the size and layout of ducting.

• Proper calculations and design are necessary to ensure safe and efficient duc...read more

Factor of safety is a measure of how much stronger a structure is than it needs to be for its intended purpose.

• Factor of safety is the ratio of the maximum load a structure can handle to the actual load it is expected to handle.

• It is used to ensure that a structure or component can withstand unexpected loads or stresses.

• For example, a bridge may have a factor of safety of 2, meaning it can handle twice the maximum expected load without failing.

• Factors of safety vary depending...read more

Cooling tower performance is measured by its ability to remove heat from a process stream.

• Cooling tower performance is affected by factors such as air flow rate, water flow rate, and temperature difference between the process stream and cooling water.

• The efficiency of a cooling tower can be improved by increasing the surface area of the heat transfer media, using a more efficient fan, or optimizing the water distribution system.

• Performance can be measured by the approach temp...read more

Heat load calculations involve determining the amount of heat that needs to be added or removed from a space to maintain a desired temperature.

• Components include heat gain from occupants, equipment, lighting, and infiltration, as well as heat loss through walls, windows, and roofs.

• Calculations are typically done using formulas based on the specific heat capacities and thermal properties of materials.

• Example: In HVAC design, heat load calculations are used to size equipment li...read more

Kaizen is continuous improvement, 5S is a workplace organization method, QA is quality assurance and QC is quality control.

• Kaizen is a Japanese term for continuous improvement in all aspects of life, including work.

• 5S is a workplace organization method that stands for Sort, Set in Order, Shine, Standardize, and Sustain.

• QA is the process of ensuring that a product or service meets the required quality standards.

• QC is the process of checking that a product or service meets the ...read more

Roller screen maintenance involves regular cleaning, lubrication, and inspection.

• Clean the rollers and screen regularly to prevent buildup of debris and dirt.

• Lubricate the rollers and bearings to ensure smooth operation.

• Inspect the rollers, bearings, and screen for wear and damage.

• Replace any worn or damaged parts immediately to prevent further damage.

• Follow manufacturer's guidelines for maintenance and schedule regular maintenance checks.

• Train personnel on proper maintenance...read more

The least count of a vernier caliper is the smallest measurement that can be accurately read on the scale.

• The least count is determined by the number of divisions on the main scale and the vernier scale.

• It is calculated by dividing the smallest division on the main scale by the number of divisions on the vernier scale.

• For example, if the smallest division on the main scale is 0.1 mm and the vernier scale has 10 divisions, the least count would be 0.01 mm.

• The least count repre...read more

A train doesn't need a differential because its wheels are fixed to the same axle and rotate at the same speed.

• Train wheels are fixed to the same axle

• Wheels rotate at the same speed

• Differential is used in vehicles with wheels that rotate at different speeds

• Differential allows for smooth turning

The clearance for big end bearing can be measured using a micrometer or a feeler gauge.

• Use a micrometer to measure the diameter of the crankshaft journal and the inner diameter of the big end bearing. The clearance is calculated by subtracting the crankshaft journal diameter from the bearing inner diameter.

• Alternatively, a feeler gauge can be used to measure the clearance by inserting the gauge between the crankshaft journal and the bearing and checking for the appropriate ga...read more