800+ Mechanical Engineer Interview Questions and Answers

Compressor is used to increase the pressure of gas while booster is used to increase the pressure of already compressed gas.

• Compressor is used to compress gas from low pressure to high pressure.

• Booster is used to increase the pressure of already compressed gas.

• Compressor is used in various applications like air conditioning, refrigeration, and gas turbines.

• Booster is used in applications like pipeline transportation of natural gas and oil refining.

• Compressor can have multiple...read more

The total budget for Chandrayaan 1 mission was approximately $79 million.

• The mission was launched by the Indian Space Research Organisation (ISRO) in 2008.

• The spacecraft was designed to orbit the Moon and perform various scientific experiments.

• The mission was considered a success despite some technical issues.

• The budget included the cost of the spacecraft, launch vehicle, ground support, and mission operations.

• The mission paved the way for future lunar exploration missions by...read more

Excel is a spreadsheet software used for organizing, analyzing and manipulating data.

• Excel allows users to create tables, charts, and graphs to represent data visually.

• It can perform complex calculations and analysis on large sets of data.

• Excel can be used for budgeting, financial analysis, project management, and more.

• It also has features for data validation, sorting, filtering, and conditional formatting.

• Excel can import and export data from other software applications.

• Exam...read more

Steering and suspension system in automobile are responsible for controlling the movement and stability of the vehicle.

• Steering system helps in changing the direction of the vehicle while suspension system ensures smooth ride and stability.

• Steering system consists of components like steering wheel, steering column, steering gear, and tie rods.

• Suspension system consists of components like shock absorbers, springs, struts, and control arms.

• The suspension system also helps in ma...read more

Steam turbine converts thermal energy in steam into mechanical energy.

• Steam enters the turbine and expands, causing the rotor to spin

• The spinning rotor is connected to a generator, producing electricity

• Used in power plants, refineries, and other industrial applications

Servo valve nas value refers to the National Aerospace Standard (NAS) specification for servo valves.

• NAS value is a standard that defines the performance and quality requirements for servo valves used in aerospace applications.

• It ensures that servo valves meet specific criteria for reliability, accuracy, and durability.

• NAS value is often used as a reference when selecting or evaluating servo valves for aerospace systems.

• The NAS value may include parameters such as flow rate, ...read more

Broaching is a machining process that uses a toothed tool to remove material. Surface finish refers to the texture of a machined surface.

• Broaching is a process of removing material using a broach tool with teeth that gradually increase in size.

• Surface finish is the texture of a machined surface, which can be measured in terms of roughness or smoothness.

• Surface finish can be improved by using different cutting tools, adjusting cutting parameters, or using finishing processes l...read more

Maximum shear stress theory is a theory used to determine the failure of materials under shear stress.

• Also known as Tresca's theory or Guest's theory

• States that failure occurs when the maximum shear stress in a material exceeds a certain value

• Used in designing materials for ductile failure

• Not applicable for brittle materials

• Formula: τmax = (σ1 - σ2) / 2

• Where σ1 and σ2 are the principal stresses

MR Braking stands for Magnetic Resistance Braking. It is a type of braking system used in trains and other vehicles.

• MR Braking uses magnetic fields to slow down or stop a vehicle.

• It is commonly used in trains as it provides a smooth and efficient braking system.

• The braking force is generated by the resistance between the magnetic field and the conductive material on the train's wheels.

• MR Braking is also used in roller coasters and other amusement park rides.

• It is a safer and ...read more

Torquing is the application of rotational force to tighten a fastener while tensioning is the application of axial force to stretch a bolt.

• Torquing involves twisting a bolt or nut to a specific tightness

• Tensioning involves stretching a bolt to a specific tightness

• Torquing is used for smaller bolts and nuts while tensioning is used for larger bolts

• Torquing is more precise than tensioning

• Examples of torquing tools include torque wrenches and screwdrivers while examples of tensi...read more

Stress is the force applied to a material, while strain is the resulting deformation. A stress-strain graph for ductile materials shows the relationship between stress and strain. Vernier calipers formula is used for precise measurements.

• Stress is the force applied per unit area on a material, measured in units like N/m^2 or Pa.

• Strain is the ratio of the change in length to the original length of a material.

• A stress-strain graph for ductile materials typically shows an initia...read more

Total head required for a pump can be calculated using Bernoulli's equation

• Determine the flow rate required

• Calculate the friction loss in the piping system

• Determine the elevation difference between the pump and the discharge point

• Add the three values to get the total head required

• Consider any additional losses due to fittings or valves

Types of pumps include centrifugal, reciprocating, rotary, and diaphragm pumps. Each pump is used for specific purposes based on its design and capabilities.

• Centrifugal pumps are commonly used for water and sewage systems.

• Reciprocating pumps are suitable for high-pressure applications like hydraulic systems.

• Rotary pumps are used for viscous fluids like oils and chemicals.

• Diaphragm pumps are ideal for handling corrosive or abrasive fluids.

Potential causes of engine starting issues include battery problems, fuel issues, ignition system faults, and mechanical issues.

• Weak or dead battery

• Fuel pump failure

• Clogged fuel filter

• Faulty spark plugs

• Ignition coil issues

• Starter motor problems

• Broken timing belt

• Low engine compression

Internal combustion engines are heat engines that burn fuel inside the engine to produce mechanical energy.

• IC engines are commonly used in vehicles, such as cars, motorcycles, and trucks.

• They work by burning fuel (usually gasoline or diesel) in a combustion chamber to create high-pressure gases that drive a piston.

• The movement of the piston is converted into rotational motion, which powers the vehicle.

• IC engines can be classified into two main types: spark-ignition engines (p...read more

Fan maintenance work involves cleaning, lubricating, and inspecting the fan components regularly.

• Clean the fan blades and housing to remove dirt and debris

• Lubricate the bearings and motor to ensure smooth operation

• Inspect the belts, pulleys, and other components for wear and tear

• Replace any damaged or worn parts as necessary

• Check the fan's alignment and balance to prevent vibration and noise issues

Tolerance in shaft and hole is achieved by specifying the acceptable range of dimensions for both components.

• Specify the desired fit (clearance, interference, transition) between the shaft and hole

• Determine the basic size of the shaft and hole

• Select the tolerance class based on the required precision

• Apply the appropriate geometric tolerances if needed

• Consider factors like material properties, manufacturing processes, and assembly requirements

• Examples: H7/g6, H8/f7, H9/h9

Limits fits and tolerances are used in engineering to determine the acceptable range of dimensions for mating parts.

• Limits are the maximum and minimum acceptable dimensions for a part

• Fits are the range of tightness or looseness between mating parts

• Tolerances are the allowable deviation from a specified dimension

• Examples: H7/g6, H8/f7, etc.

A vacuum is a space devoid of matter. I have used a rotary vane vacuum pump.

• A vacuum is a region with no particles or gas molecules.

• It is created by removing air or other gases from a sealed container.

• Vacuum pumps are used to create and maintain a vacuum.

• I have used a rotary vane vacuum pump, which uses rotating vanes to create a vacuum.

• This type of pump is commonly used in various applications, such as in HVAC systems, laboratories, and industrial processes.

Centroid and center of gravity are similar concepts, but differ in their applications and calculations.

• Centroid is the geometric center of a shape, while center of gravity is the point where the total weight of an object is considered to act.

• Centroid is used in statics and geometry, while center of gravity is used in physics and mechanics.

• Centroid can be calculated using geometric properties, such as area or volume, while center of gravity depends on the distribution of mass....read more

Mechanical seals are of two types - balanced and unbalanced. The difference lies in the design and application.

• Balanced mechanical seals have a secondary seal that balances the pressure on both sides of the seal faces, reducing the risk of leakage and wear.

• Unbalanced mechanical seals do not have a secondary seal and rely on the pressure difference between the seal faces to maintain the seal.

• Balanced seals are used in high-pressure applications, while unbalanced seals are used...read more

There are three types of safety: personal safety, general safety, and machine safety.

• Personal safety involves protecting oneself from harm or injury.

• General safety pertains to the safety of the environment and people around us.

• Machine safety involves ensuring that machines are safe to operate and do not pose a threat to workers.

• Examples of personal safety measures include wearing protective gear, such as helmets and gloves, and following safety protocols.

• Examples of general s...read more

Yield strength is the stress at which a material begins to deform plastically, while ultimate strength is the maximum stress a material can withstand before breaking.

• Yield strength is the point where a material starts to deform plastically, meaning it will not return to its original shape once the stress is removed.

• Ultimate strength is the maximum stress a material can withstand before it breaks or fractures.

• Yield strength is typically lower than ultimate strength.

• Both yield ...read more

Stress-strain diagrams of MS and cast iron.

• Mild Steel: linear elastic up to yield point, plastic deformation after that, ultimate strength at fracture point.

• Cast Iron: brittle material, low ductility, low yield strength, high compressive strength.

• MS has higher tensile strength than cast iron.

• MS has higher elongation at break than cast iron.

Fuel is combusted in a diesel engine through a process called compression ignition.

• Air is compressed in the cylinder, causing it to heat up

• Fuel is injected into the cylinder at the right time

• The heat from the compressed air ignites the fuel

• The resulting explosion pushes the piston down, creating power

• Diesel engines do not use spark plugs like gasoline engines

A centrifugal pump is a mechanical device that uses centrifugal force to transport fluids. There are two types: radial and axial.

• Centrifugal pumps are commonly used in industrial and domestic applications.

• Radial pumps have a volute casing and are used for low flow and high head applications.

• Axial pumps have a propeller and are used for high flow and low head applications.

• Centrifugal pumps are easy to install and maintain.

• They are not suitable for high viscosity fluids or flui...read more

Seam welding is a process of joining two metal sheets by creating a continuous seam along the joint. Bending of pipes is the process of shaping pipes into desired angles or curves. Welding materials are the materials used in welding processes.

• Seam welding is commonly used in the automotive and aerospace industries.

• Bending of pipes is done using specialized tools like pipe benders.

• Welding materials include filler metals, fluxes, and shielding gases.

• The choice of welding materi...read more

The distance between two supports in a single run pipe depends on the material, size, and weight of the pipe.

• The distance between supports for steel pipes is typically 10-12 feet.

• For PVC pipes, the distance can be shorter, around 4-5 feet.

• Consider factors like pipe material, size, weight, temperature, and pressure when determining support spacing.

Ackerman steering system is still widely used in modern vehicles for better maneuverability and turning radius.

• Ackerman steering geometry ensures that all wheels follow different turning radii during a turn

• It helps in reducing tire wear and improving vehicle stability during turns

• Modern vehicles like sports cars, trucks, and even some electric vehicles still use Ackerman steering system

Transmission shaft in automobiles transmits power from the engine to the wheels.

• Transmits power from the engine to the wheels

• Helps in changing the speed and torque of the vehicle

• Connects the engine to the wheels through the gearbox and differential

• Can be a single-piece shaft or a two-piece shaft in some vehicles

Quality control of press components involves ensuring that the manufactured parts meet the required specifications and standards.

• Inspecting the press components for defects and deviations from the required specifications

• Using various measuring tools and techniques to ensure accuracy and precision

• Documenting and reporting any non-conformities and taking corrective actions

• Collaborating with production and design teams to improve the manufacturing process

• Ensuring compliance with...read more

The magnetic axis is an imaginary line that represents the direction of the magnetic field in a magnetic object.

• The magnetic axis is calculated by determining the average direction of the magnetic field in the object.

• It is often determined using magnetic sensors or compasses.

• The magnetic axis is important in understanding the behavior and properties of magnetic materials.

• It helps in designing and analyzing magnetic devices and systems.

• For example, in a permanent magnet, the m...read more

Stress is the force applied per unit area, while strain is the deformation caused by stress.

• Stress is measured in units of force per unit area, such as pounds per square inch (psi) or newtons per square meter (N/m²).

• Strain is the ratio of the change in length or shape of an object to its original length or shape.

• Stress and strain are related by the material's modulus of elasticity, which is a measure of how much the material will deform under stress.

• The stress-strain diagram ...read more

A motor using water and kerosene is likely a type of internal combustion engine.

• It likely uses a mixture of water and kerosene as fuel.

• The water helps to cool the engine and reduce emissions.

• This type of engine may be used in certain types of boats or generators.

• It may also be referred to as a water-injection engine.

Mechanical seal installation, assembly, and disassembly require proper tools and techniques to ensure a leak-free operation.

• Choose the right type of mechanical seal for the application

• Clean and inspect all components before installation

• Use a proper lubricant to prevent damage during assembly

• Tighten bolts in a criss-cross pattern to ensure even pressure

• Follow manufacturer's instructions for disassembly and reassembly

• Inspect and replace worn or damaged components as necessary

Production is the process of creating goods or services, while manufacturing is the specific process of making products.

• Production involves the entire process of creating goods or services, including planning, designing, and delivering.

• Manufacturing is a subset of production and refers specifically to the process of making products.

• Production can include non-tangible items like software or services, while manufacturing typically involves physical products.

• Examples of producti...read more

Types of boilers include fire tube, water tube, and electric boilers. ESP is a device used to remove particles from exhaust gas. Thermodynamic cycles include Carnot, Rankine, and Brayton cycles.

• Types of boilers: fire tube, water tube, electric

• ESP: device to remove particles from exhaust gas

• Thermodynamic cycles: Carnot, Rankine, Brayton

Equipment installation involves setting up machinery and ensuring it operates correctly.

• Understanding technical specifications and blueprints

• Assembling and connecting components

• Testing and troubleshooting

• Adhering to safety regulations

• Collaborating with other professionals

• Examples: installing HVAC systems, manufacturing equipment, or production lines

Balancing disc in boiler feed pump helps to reduce axial thrust and maintain stability.

• Balancing disc is a rotating disc placed between the impeller and the shaft.

• It helps to balance the hydraulic forces acting on the impeller.

• Reduces axial thrust and maintains stability of the pump.

• Improves the life of bearings and other components.

• Example: KSB boiler feed pump has a balancing disc for stable operation.

Pump head calculation involves determining the pressure required to move fluid through a piping system.

• Determine the flow rate of the fluid

• Calculate the friction loss in the piping system

• Add the elevation difference between the inlet and outlet of the pump

• Consider any additional pressure requirements such as for filters or heat exchangers

Proper environment, rules and regulations are necessary for safety, efficiency and productivity.

• Proper environment ensures the safety of workers and equipment.

• Rules and regulations ensure compliance with legal and ethical standards.

• Proper environment, rules and regulations promote efficiency and productivity.

• Lack of proper environment, rules and regulations can lead to accidents, injuries, and loss of productivity.

• Examples include lack of safety equipment, inadequate ventilat...read more

The operating pressure of the Epiroc 1500 Breaker is typically around 1600 psi.

• The Epiroc 1500 Breaker is a hydraulic breaker used for breaking rocks and concrete.

• The operating pressure refers to the pressure at which the hydraulic system of the breaker operates.

• The operating pressure can vary depending on the specific model and application.

• For the Epiroc 1500 Breaker, the typical operating pressure is around 1600 psi.

• This pressure allows the breaker to generate sufficient fo...read more

Innovation, cybersecurity, data analytics, automation, and cloud computing are important in the IT sector.

• Innovation drives technological advancements and competitive edge.

• Cybersecurity is crucial to protect sensitive data and systems from cyber threats.

• Data analytics helps in making informed decisions and improving business processes.

• Automation streamlines repetitive tasks and increases efficiency.

• Cloud computing enables scalability, flexibility, and cost-effectiveness.

There are various inserts used for threading depending on the material being threaded and the type of thread required.

• The most common inserts are carbide inserts, ceramic inserts, and high-speed steel inserts.

• Carbide inserts are suitable for threading hard materials like stainless steel and titanium.

• Ceramic inserts are used for high-speed threading of aluminum and other non-ferrous materials.

• High-speed steel inserts are used for general-purpose threading of softer materials l...read more

The main parts of a centrifugal compressor include impeller, diffuser, volute, inlet guide vanes, and discharge nozzle.

• Impeller: Rotating component that imparts kinetic energy to the fluid.

• Diffuser: Converts kinetic energy into pressure energy.

• Volute: Collects the compressed fluid and directs it to the discharge nozzle.

• Inlet guide vanes: Control the flow of fluid into the impeller.

• Discharge nozzle: Releases the compressed fluid at high pressure.

Hollow shaft transmits more power than solid shaft.

• Hollow shaft has a larger moment of inertia, allowing it to handle more torque.

• Hollow shaft has a larger cross-sectional area, reducing stress and increasing power transmission capacity.

• Hollow shaft can be designed with thicker walls, increasing its strength and power transmission capability.

• Examples: Hollow steel shafts used in automotive drive shafts, hollow aluminum shafts used in aircraft propellers.

A single point cutting tool is a tool used in machining to remove material from a workpiece. It has a pointed end and various angles.

• The tool has a pointed end that is used to cut the material.

• The angle of the tool is important for achieving the desired cut.

• The angle of the tool is measured in relation to the workpiece.

• Common angles for single point cutting tools include 60 degrees, 75 degrees, and 90 degrees.

• The angle of the tool can be adjusted to achieve different cuts and...read more