90+ Junior Mechanical Engineer Interview Questions and Answers

Types of gearboxes include spur, helical, bevel, worm, and planetary. The most commonly used gearbox in our plant is the helical gearbox.

• Types of gearboxes: spur, helical, bevel, worm, planetary

• Helical gearbox is commonly used for its efficiency and smooth operation

• Spur gearbox is simple and cost-effective

• Bevel gearbox is used for right angle drives

• Worm gearbox provides high torque but lower efficiency

To improve cycle time, focus on process optimization and efficiency. Rejection control involves identifying root causes of defects and implementing corrective actions.

• Implement lean manufacturing principles to streamline processes and reduce waste

• Utilize automation and technology to speed up production

• Regularly analyze data and performance metrics to identify bottlenecks and areas for improvement

• Train employees on best practices and quality standards to reduce errors and defe...read more

The major steel plants in India include Tata Steel, JSW Steel, SAIL, and Essar Steel. Compressors are devices that increase the pressure of a gas or air.

• Major steel plants in India include Tata Steel, JSW Steel, SAIL, and Essar Steel

• Compressors are devices that increase the pressure of a gas or air

• Types of compressors include reciprocating, rotary screw, centrifugal, and axial flow compressors

• Major steel plants in Chennai include the Chennai Steel Plant and the Madras Steel P...read more

Air mainly contains water vapor due to the evaporation of water bodies, plants, and human activities.

• Water vapor is the most abundant gas in the atmosphere due to evaporation from oceans, lakes, rivers, and plants.

• Other vapors like alcohol, gasoline, or perfume are present in the air but in much lower concentrations compared to water vapor.

• Water vapor is constantly being added to the air through processes like transpiration from plants and evaporation from human activities li...read more

The formula for calculating stress and strain in materials is based on Hooke's Law.

• Stress (σ) = Force (F) / Area (A)

• Strain (ε) = Change in length (ΔL) / Original length (L)

• Hooke's Law: Stress = Young's Modulus x Strain

• Example: If a force of 100 N is applied to a material with a cross-sectional area of 2 m^2, the stress would be 50 N/m^2

Key features for installation of Power Plant include location selection, environmental impact assessment, equipment installation, and safety measures.

• Location selection is crucial for accessibility to resources and transmission lines.

• Environmental impact assessment must be conducted to ensure compliance with regulations.

• Proper installation of equipment such as turbines, generators, and transformers is essential for efficient operation.

• Safety measures like fire protection syst...read more

Gases in the atmosphere do not separate out according to mass due to the constant mixing caused by wind and turbulence.

• Constant mixing caused by wind and turbulence prevents gases from separating based on mass

• Gravity also plays a role in keeping gases well-mixed in the atmosphere

• Different gases have different molecular weights but are still evenly distributed in the atmosphere

Conventional power plants use fossil fuels to generate electricity while non-conventional power plants use renewable sources.

• Conventional power plants burn fossil fuels like coal, oil, and natural gas to generate electricity

• Non-conventional power plants use renewable sources like solar, wind, hydro, and geothermal energy

• Conventional power plants are cheaper to build and operate but contribute to pollution and climate change

• Non-conventional power plants are more expensive to b...read more

The interview questions cover topics such as engine types, tire color, CC, hydraulic systems, and safety.

• Two-stroke and four-stroke engines differ in their combustion cycles

• Diesel and petrol engines use different types of fuel

• The black color of tires is due to the carbon black added to the rubber during manufacturing

• CC stands for cubic centimeters and is a measure of engine displacement

• Hydraulic systems use fluids to transmit power and control machinery

• Safety is an important ...read more

The number of temp. required to melt mild steel depends on the specific grade of steel. Syco cranes are used for heavy lifting. Different types of gears can be used based on the application. Various types of pumps can be used depending on the requirements. Head refers to the pressure generated by a pump. Alignment is crucial for proper functioning of mechanical systems.

• Number of temp. required to melt mild steel depends on the grade of steel

• Syco cranes are used for heavy lift...read more

Yes, I have done pre-maintenance of equipment and tracked maintenance status.

• I have conducted regular inspections of equipment to identify potential issues before they become major problems.

• I have kept detailed records of maintenance activities, including dates, tasks performed, and any issues encountered.

• I have worked with maintenance teams to develop and implement preventative maintenance plans.

• I have used software tools to track maintenance schedules and generate reports o...read more

The fabrication of a structure requires detailed fabrication drawings.

• Fabrication drawings provide detailed information on the dimensions, materials, and assembly of the structure.

• These drawings are typically created by a structural engineer or draftsman.

• They may include plans, elevations, sections, and details of the structure.

• Fabrication drawings are essential for ensuring that the structure is built to the correct specifications and meets safety standards.

• Examples of struc...read more

There are mainly three types of bearings nomenclature: ball bearings, roller bearings, and plain bearings.

• Ball bearings

• Roller bearings

• Plain bearings

Thermal power plant generates electricity by converting heat energy into electrical energy.

• Fuel is burned to produce heat

• Heat is used to produce steam

• Steam drives the turbine

• Turbine drives the generator

• Generator produces electricity

• Examples: coal-fired power plant, gas-fired power plant, nuclear power plant

The type of reducer used in pipe rack depends on the specific application and requirements.

• Reducers are used to connect pipes of different sizes in a pipe rack.

• The type of reducer used depends on the size and material of the pipes being connected.

• Common types of reducers include concentric, eccentric, and swage reducers.

• Concentric reducers have a symmetrical shape and are used when pipes of different sizes need to be connected in a straight line.

• Eccentric reducers have an off...read more

Priming is the process of removing air from the pump and filling it with liquid. Head of pump is the height to which the pump can raise water.

• Priming is done to remove air from the pump and fill it with liquid to ensure proper functioning.

• Head of pump is the maximum height to which the pump can raise water.

• Priming is necessary for self-priming pumps, while non-self-priming pumps require manual priming.

• Head of pump is affected by factors such as pump speed, impeller diameter, ...read more

Clouds move due to the combination of wind, temperature, and pressure differences in the atmosphere.

• Clouds are carried along by the wind in the atmosphere.

• Temperature differences cause air to rise or sink, affecting cloud movement.

• Pressure variations also play a role in cloud motion.

• For example, warm air rising from the ground can create cumulus clouds that move with the wind.

Oil consumption of an engine per hour can be calculated by measuring the difference in oil level before and after a certain period of time.

• Calculate the initial oil level in the engine.

• Run the engine for a specific number of hours.

• Measure the final oil level in the engine.

• Subtract the final oil level from the initial oil level to determine the amount of oil consumed per hour.

• Divide the amount of oil consumed by the number of hours the engine ran to get the oil consumption per...read more

Engineering materials include metals, polymers, ceramics, and composites. Stress-strain refers to the relationship between applied force and deformation.

• Engineering materials include metals, polymers, ceramics, and composites

• Metals have high strength and ductility, such as steel and aluminum

• Polymers are lightweight and flexible, like plastics and rubber

• Ceramics are hard and brittle, such as glass and ceramics

• Composites are combinations of different materials, like carbon fibe...read more

The process for selecting a pump involves determining the required flow rate, head, type of fluid, system characteristics, and budget constraints.

• Identify the required flow rate and head for the system

• Consider the type of fluid being pumped (e.g. water, oil, chemicals)

• Evaluate the system characteristics such as pressure, temperature, and viscosity

• Take into account budget constraints and operational costs

• Select a pump type that meets the requirements identified

Process piping refers to the system of pipes used to transport fluids in industrial settings.

• Process piping is used in various industries such as oil and gas, chemical, pharmaceutical, and food processing.

• It is designed to safely transport liquids, gases, and solids from one point to another within a facility.

• Process piping systems include pipes, fittings, valves, and other components to control the flow of materials.

• Proper design and installation of process piping is crucial...read more

Isometric drawings are required for fabrication of pipelines.

• Isometric drawings show the 3D view of the pipeline and its components.

• They include information about the size, shape, and orientation of the pipes.

• Isometric drawings also show the location of valves, fittings, and other components.

• These drawings are used by fabricators to create the pipeline according to the design.

• Other types of drawings that may be required include P&IDs and equipment layout drawings.

Thermal power plants use fossil fuels to generate electricity. They have advantages and disadvantages.

• Advantages: Reliable source of electricity, low operating cost, high efficiency, easy to operate and maintain

• Disadvantages: High initial cost, environmental pollution, non-renewable source of energy, limited availability of fuel

• Example: Advantages - Thermal power plants provide a reliable source of electricity that can be generated 24/7. They have low operating costs and high...read more

OEE stands for Overall Equipment Effectiveness, a measure of how well a manufacturing process is utilized.

• OEE is calculated by multiplying Availability, Performance, and Quality percentages.

• Availability = (Operating Time / Planned Production Time) * 100

• Performance = (Ideal Cycle Time / Total Count) * 100

• Quality = (Good Count / Total Count) * 100

• OEE = Availability * Performance * Quality

• For example, if a machine operates for 8 hours out of a planned 10 hours, with an ideal cyc...read more

Co-Generation plants are power plants that produce both electricity and useful heat simultaneously.

• Co-Generation plants are also known as Combined Heat and Power (CHP) plants.

• They use a single fuel source to generate both electricity and heat.

• The heat produced during electricity generation is captured and used for heating buildings or industrial processes.

• Co-Generation plants are more efficient than traditional power plants because they utilize the waste heat that is normally...read more

Thermodynamic cycles and PV TS diagrams are fundamental concepts in mechanical engineering.

• Thermodynamic cycles are processes that involve the transfer of heat and work between a system and its surroundings.

• PV TS diagrams are graphical representations of thermodynamic processes.

• Examples of thermodynamic cycles include the Carnot cycle, Rankine cycle, and Brayton cycle.

• PV TS diagrams can be used to analyze the efficiency and performance of thermodynamic systems.

• Understanding t...read more

Sheet metal processing methods include cutting, bending, forming, and joining techniques.

• Cutting: Shearing, laser cutting, water jet cutting

• Bending: Press brake bending, roll bending

• Forming: Stamping, deep drawing, spinning

• Joining: Welding, riveting, adhesive bonding

Major CNC breakdowns include electrical, mechanical, and software issues. Preventive maintenance includes regular cleaning and lubrication.

• Electrical breakdowns can be caused by power surges or faulty wiring.

• Mechanical breakdowns can be caused by worn out parts or improper alignment.

• Software breakdowns can be caused by bugs or outdated programs.

• Preventive maintenance includes regular cleaning of the machine and lubrication of moving parts.

• Regular inspection of the machine can...read more

Elastic city limit refers to the maximum distance a city can expand while still maintaining its infrastructure and services.

• Elastic city limit is determined by factors such as transportation networks, utilities, and population density.

• Cities often face challenges in managing urban sprawl beyond their elastic limits.

• Examples of cities with well-defined elastic limits include Tokyo, New York City, and London.

There are a total of ten furnaces, with five of them being panel furnaces and one VIP Duraline furnace.

• Total of 10 furnaces

• 5 of them are panel furnaces

• 1 VIP Duraline furnace

Tariff is a tax imposed on imported or exported goods. It is analyzed based on the type of goods and the country of origin/destination.

• Tariff is a form of protectionism used by governments to protect domestic industries from foreign competition.

• Tariffs can be specific (fixed amount per unit) or ad valorem (percentage of the value of the goods).

• Tariffs can also be used as a tool for diplomacy, by imposing tariffs on countries that do not comply with certain policies or agreeme...read more

To check SS 304 and SS 316 pipes, one can use various methods such as visual inspection, magnetic testing, and chemical analysis.

• Visual inspection can be done to check for any surface defects or irregularities.

• Magnetic testing can differentiate between the two types of pipes as SS 316 is non-magnetic while SS 304 is magnetic.

• Chemical analysis can be done to determine the exact composition of the pipes.

• X-ray testing can also be used to check for any internal defects or inconsi...read more

I have worked with a variety of materials, including metals, plastics, and composites.

• Experience with machining processes such as milling, turning, and drilling.

• Proficient in designing CAD models using software like SolidWorks or AutoCAD.

• Knowledge of material properties and selection for specific applications.

• Understanding of manufacturing processes and their impact on material selection and design.

• Ability to analyze and optimize designs for cost, performance, and manufactura...read more

Packing plate location is crucial for stability and alignment of the base frame.

• Ensure packing plates are placed evenly on all sides of the base frame to distribute weight properly.

• Use appropriate thickness of packing plates to achieve desired height and levelness.

• Check for any gaps or misalignments after mounting the base frame to ensure stability.

• Consider using shims or adjustable feet for fine-tuning the levelness of the base frame.

Types of loads considered in designing steel structures include dead load, live load, wind load, snow load, and seismic load.

• Dead load: the weight of the structure itself and any permanent fixtures

• Live load: the weight of occupants, furniture, and other temporary loads

• Wind load: the force exerted by wind on the structure

• Snow load: the weight of snow on the structure

• Seismic load: the force exerted by earthquakes on the structure

Vernier caliper is a precision measuring tool used to accurately measure dimensions of objects.

• Vernier caliper has a main scale and a sliding vernier scale for more precise measurements.

• It can measure internal dimensions, external dimensions, and depth of objects.

• The accuracy of a vernier caliper is typically up to 0.02 mm.

• Example: Measuring the diameter of a small rod using a vernier caliper.

Types of alignment include shaft alignment, coupling alignment, and belt alignment. Each process involves ensuring components are properly positioned for optimal performance.

• Shaft alignment involves aligning the shafts of rotating machinery to prevent vibration and wear.

• Coupling alignment ensures that the coupling connecting two shafts is properly aligned to prevent misalignment issues.

• Belt alignment involves aligning belts on pulleys to prevent slippage and ensure efficient ...read more

Autonomous maintenance is a maintenance strategy where operators are responsible for routine maintenance tasks.

• Autonomous maintenance involves operators taking ownership of basic maintenance tasks such as cleaning, lubricating, and inspecting equipment.

• The goal of autonomous maintenance is to prevent breakdowns and improve overall equipment effectiveness.

• Operators are trained to identify abnormalities and address them before they lead to more serious issues.

• Autonomous mainten...read more

Lean manufacturing is a production method aimed at minimizing waste and maximizing efficiency.

• Focuses on continuous improvement

• Eliminates waste in processes

• Involves just-in-time production

• Uses tools like value stream mapping and 5S

• Promotes employee involvement and empowerment

Rework analysis involves identifying and addressing issues in a product or process to improve efficiency and quality.

• Rework analysis is a process of examining and evaluating the reasons for rework in a project or product.

• It involves identifying root causes of defects or errors and implementing corrective actions to prevent future rework.

• Examples of rework analysis include conducting failure mode and effects analysis (FMEA) to identify potential failure modes and their causes,...read more

A bearing is considered failed when it shows signs of excessive wear, noise, vibration, or overheating.

• Excessive noise during operation

• Vibration felt in the equipment

• Overheating of the bearing

• Visible signs of wear or damage on the bearing surface

• Loss of lubrication leading to increased friction

Drums are used in Benson boilers for steam separation and circulation.

• Benson boilers are a type of supercritical boilers used in power plants.

• Drums are used for steam-water separation and circulation.

• The number of drums used in a Benson boiler depends on the design and capacity.

• Some Benson boilers may have one or two drums.

• Drums are also used in other types of boilers for similar purposes.

Fabrication is the process of creating a product by cutting, shaping, and assembling materials.

• Fabrication involves cutting, bending, welding, and assembling raw materials to create a final product.

• Common fabrication processes include machining, casting, forging, and stamping.

• Examples of fabricated products include metal structures, machinery parts, and electronic components.

Through curve mesh is a 3D model created by connecting points on a curve, while through curve is a command used in CAD software to create a curve passing through specified points.

• Through curve mesh is a 3D model created by connecting points on a curve to form a mesh surface.

• Through curve command in CAD software is used to create a curve passing through specified points or existing curves.

• Through curve mesh is commonly used in 3D modeling for creating complex surfaces, while t...read more

The number of gauges used for measurement varies depending on the specific project or application.

• The number of gauges used for measurement can range from a few to several dozen, depending on the complexity of the system being measured.

• Examples of gauges commonly used for measurement include pressure gauges, temperature gauges, flow meters, and level gauges.

• The specific gauges used will depend on the parameters being measured and the accuracy required for the project.

PPM stands for parts per million, a unit of measurement used to describe the concentration of a substance in a solution.

• PPM is commonly used in various industries such as manufacturing, environmental monitoring, and water treatment.

• It is used to express very small concentrations of pollutants or chemicals in air, water, soil, etc.

• For example, if a water sample contains 5 ppm of lead, it means there are 5 parts of lead for every million parts of water.

Scrap count refers to the number of defective or unusable parts produced during manufacturing.

• Scrap count is an important metric in manufacturing to track quality control and efficiency.

• It helps identify areas of improvement in the production process.

• Examples of scrap count include parts with manufacturing defects, incorrect dimensions, or damaged during production.