40+ Trainee Mechanical Engineer Interview Questions and Answers

Specific gravity varies for different materials. Aluminium - 2.7, Tungsten - 19.3, Mild Steel - 7.85, Stainless Steel - 7.9

• Specific gravity is the ratio of the density of a substance to the density of a reference substance.

• Aluminium has a specific gravity of 2.7, making it a lightweight metal.

• Tungsten has a specific gravity of 19.3, making it a very dense metal.

• Mild steel has a specific gravity of 7.85, making it a relatively heavy metal.

• Stainless steel has a specific gravity...read more

Yes, I have experience using E3D software for designing and modeling mechanical components.

• I have used E3D software extensively during my internship at XYZ Engineering firm

• I have created 3D models of various mechanical components using E3D software

• I am familiar with the features and tools of E3D software for efficient design and analysis

There are several types of production processes, including batch production, mass production, continuous production, and job production.

• Batch production involves producing a specific quantity of products at a time, often in response to customer orders.

• Mass production is characterized by the production of large quantities of standardized products using assembly lines.

• Continuous production refers to the uninterrupted production of goods, typically in industries like oil refinin...read more

Boring enlarges existing holes while reaming improves the surface finish and accuracy of holes.

• Boring is used to enlarge existing holes to a specific diameter, while reaming is used to improve the surface finish and accuracy of holes.

• Boring is typically done before reaming in the machining process.

• Boring is usually done using a single-point cutting tool, while reaming is done using a multi-edge cutting tool.

• Examples: Boring a hole in a cylinder block to fit a piston, and then...read more

Welding electrode parameters and code for overhead welding.

• Welding electrode parameters include diameter, current type, and coating type.

• For overhead welding, the given code is AWS D1.3.

• Electrode diameter should be smaller for overhead welding to prevent dripping.

• Coating type should be low-hydrogen for overhead welding to prevent porosity.

• Current type should be DC- for overhead welding to prevent arc blow.

1st and 3rd angle projection are two methods of representing a 3D object on a 2D plane in engineering drawings.

• 1st angle projection is commonly used in Europe and Asia, while 3rd angle projection is commonly used in North America.

• In 1st angle projection, the object is imagined to be in between the viewer and the plane of projection, while in 3rd angle projection, the object is imagined to be behind the plane of projection.

• The symbol for 1st angle projection is a square with a...read more

Force is a physical quantity that changes the state of motion of an object. Its SI unit is Newton (N).

• Force is a push or pull that can change the motion of an object.

• It is a vector quantity, meaning it has both magnitude and direction.

• The SI unit of force is Newton (N), named after Sir Isaac Newton.

• 1 N is defined as the force required to accelerate a mass of 1 kg at a rate of 1 m/s^2.

• Other common units of force include pound-force (lbf) and kilogram-force (kgf).

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

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

• The formula to calculate least count is: (1 main scale division) / (number of divisions on vernier scale)

• For example, if the main scale has 10 divisions and the vernier scale has 9 divisions, the least count would be 0.1 mm.

• Least count is important for accurate measurements and should be...read more

1 mm = 1000 micron

• 1 mm is equal to 1000 microns

• Micron is a unit of measurement equal to one millionth of a meter

• Micron is commonly used in the field of engineering and manufacturing

Recrystallization temperature is the temperature at which a material undergoes recrystallization to relieve internal stresses.

• Recrystallization temperature is specific to each material and is influenced by factors such as composition, impurities, and processing history.

• It is the temperature at which new grains form within the material, replacing the deformed grains to reduce internal stresses.

• Recrystallization temperature is crucial in heat treatment processes to improve the ...read more

Welding is a process of joining two or more metal pieces together by melting and fusing them.

• Types of welding include MIG (Metal Inert Gas), TIG (Tungsten Inert Gas), Stick, and Flux-Cored welding.

• Welding can be done using different heat sources like gas flame, electric arc, laser, or ultrasound.

• Common welding techniques involve fusion welding, resistance welding, and solid-state welding.

• Examples of welded products include pipelines, bridges, automotive parts, and metal furni...read more

Bending moment is the measure of the bending effect on a beam when an external force is applied to it.

• Bending moment is the product of the force applied and the distance from the force to the point of support.

• It causes the beam to bend and can lead to failure if the stress exceeds the material's strength.

• Cantilever beams have one end fixed and the other end free, making them more susceptible to bending moments.

• Bending moment can be calculated using the formula M = F x L, wher...read more

Positive drive is when power is transmitted from the driver to the driven shaft, while negative drive is when power is transmitted from the driven shaft to the driver.

• Positive drive is used in most machines and vehicles, where the power is transmitted from the engine to the wheels or other components.

• Negative drive is used in some machines, such as wind turbines, where the blades are turned by the wind and the generator is driven by the blades.

• Positive drive is more efficient...read more

Forced vibration depends on time function due to the periodic nature of the external force.

• Forced vibration is caused by an external force acting on a system.

• The external force is usually periodic in nature.

• The response of the system to the external force is also periodic.

• The time function of the external force determines the frequency and amplitude of the system's response.

• Examples include a car driving over a speed bump or a bridge vibrating due to wind.

Shear force and bending moment diagrams show internal forces in a beam under given loads.

• Shear force diagram shows the variation of shear force along the length of the beam.

• Bending moment diagram shows the variation of bending moment along the length of the beam.

• Shear force is the sum of all vertical forces acting to the left or right of a point on the beam.

• Bending moment is the sum of all moments acting to the left or right of a point on the beam.

• Both diagrams are essential ...read more

The vapor absorption cycle is a refrigeration process using heat to drive the cooling effect, utilizing a refrigerant and absorbent.

• The cycle consists of four main components: evaporator, absorber, generator, and condenser.

• In the evaporator, the refrigerant absorbs heat, causing it to evaporate and create a cooling effect.

• The absorber combines the refrigerant vapor with an absorbent, typically lithium bromide or water, to form a solution.

• The generator heats the solution, caus...read more

Engineering designs involve creating plans and specifications for structures, machines, systems, or processes.

• Engineering designs are detailed plans and specifications created to solve specific problems or meet certain requirements.

• Designs can include drawings, calculations, simulations, and prototypes to ensure functionality and safety.

• Engineers use principles of physics, mathematics, and materials science to develop efficient and cost-effective designs.

• Examples of engineeri...read more

Heat treatment is a process used to alter the physical and sometimes chemical properties of a material through controlled heating and cooling.

• Heat treatment involves heating a material to a specific temperature, holding it at that temperature for a certain amount of time, and then cooling it at a controlled rate.

• The purpose of heat treatment is to improve the material's hardness, strength, toughness, ductility, and other properties.

• Common heat treatment processes include anne...read more

Derive power equation in pipe flow for given head.

• Power equation in pipe flow is given by P = Q * H * ρ * g

• Where P is power, Q is flow rate, H is head, ρ is density and g is acceleration due to gravity

• Power equation can be derived using Bernoulli's equation and conservation of energy principle

CNC stands for Computer Numerical Control.

• CNC is a manufacturing process that uses computerized controls to operate and manipulate machine tools.

• It involves the use of software to control the movement and operation of machinery, such as lathes, mills, routers, and grinders.

• CNC machines are used in a variety of industries, including automotive, aerospace, and electronics manufacturing.

• Examples of CNC machines include CNC mills, CNC lathes, CNC routers, and CNC plasma cutters.

Design considerations for conveyor belts for load transmission include material selection, belt width, pulley diameter, and tensioning system.

• Material selection: Choose a material that can withstand the load and environment conditions.

• Belt width: Ensure the belt width is appropriate for the size and weight of the load.

• Pulley diameter: Select pulleys with the right diameter to prevent belt slippage.

• Tensioning system: Implement a proper tensioning system to maintain belt tensio...read more

Diesel engines use compression ignition while petrol engines use spark ignition.

• Diesel engines use compression ignition, where the fuel-air mixture is ignited by the heat of high compression, while petrol engines use spark ignition, where a spark plug ignites the fuel-air mixture.

• Diesel engines are more fuel efficient than petrol engines due to higher compression ratios and energy content of diesel fuel.

• Petrol engines generally have higher power output and acceleration compar...read more

I have worked on AutoCAD, SolidWorks, and ANSYS for designing mechanical components and systems.

• Proficient in AutoCAD for 2D drafting and SolidWorks for 3D modeling

• Experience in using ANSYS for finite element analysis (FEA) simulations

• Designed mechanical components such as gears, shafts, and brackets using these softwares

Otto cycle and Brayton cycle are thermodynamic cycles used in internal combustion engines and gas turbines respectively.

• Otto cycle is a four-stroke cycle used in spark-ignition engines.

• It consists of four processes: intake, compression, power, and exhaust.

• Brayton cycle is a thermodynamic cycle used in gas turbines.

• It consists of four processes: compression, combustion, expansion, and exhaust.

• Both cycles involve the conversion of heat into mechanical work.

First angle projection and third angle projection are two methods of creating a 2D drawing of a 3D object.

• First angle projection is commonly used in Europe and Asia, while third angle projection is commonly used in North America.

• In first angle projection, the object is placed in front of the viewing plane and the planes of projection are between the object and the viewer.

• In third angle projection, the object is placed behind the viewing plane and the planes of projection are ...read more

The direction of gears depends on the type of gear and its application.

• Spur gears rotate in opposite directions when meshed together.

• Helical gears rotate in the same direction when meshed together.

• Bevel gears change the direction of rotation by 90 degrees.

• Worm gears can rotate in either direction depending on the orientation of the worm and gear.

• The direction of rotation can also be reversed by adding an idler gear.

Yes, 1 mm is equal to 1000 microns.

• 1 mm = 1000 microns

• Micron is a unit of measurement for length equal to one millionth of a meter

• Microns are commonly used in the field of engineering and manufacturing

Cooling towers are used to remove heat from a building or industrial process by transferring it to the atmosphere.

• Cooling towers are commonly used in HVAC systems, power plants, and manufacturing processes.

• They work by evaporating a small amount of water to remove heat from the rest of the water circulating through the system.

• The cooled water is then recirculated back into the system to absorb more heat.

• Cooling towers can be either open-loop or closed-loop systems, depending ...read more

Fe-C diagram is a graphical representation of the phases present in steel at different temperatures and compositions.

• Fe-C diagram stands for Iron-Carbon diagram

• It shows the phases of steel at different temperatures and compositions

• It helps in understanding the microstructure of steel and predicting its properties

• Examples of phases shown in Fe-C diagram include ferrite, austenite, cementite, and pearlite

Bearings are components that allow for smooth rotation or linear motion between two parts.

• Types of bearings include ball bearings, roller bearings, plain bearings, and fluid bearings.

• Ball bearings use balls to reduce friction between two surfaces.

• Roller bearings use cylindrical rollers to support radial and axial loads.

• Plain bearings have a sliding surface instead of balls or rollers.

• Fluid bearings use a thin layer of liquid or gas to support the moving parts.

Follow up matrix tracks progress of tasks in a project. Critical path is the longest path in the project that determines the project duration.

• Follow up matrix helps in identifying the status of each task in a project and ensures timely completion.

• Critical path analysis helps in identifying the tasks that are critical to the project timeline and need to be completed on time.

• By focusing on the critical path, project managers can ensure that the project is completed within the g...read more

CNC machines are computer-controlled machines used for precision cutting, drilling, and shaping of materials.

• Milling machines - used for cutting and shaping solid materials

• Lathes - used for shaping cylindrical or spherical materials

• Drilling machines - used for drilling holes in materials

• Grinding machines - used for grinding and smoothing surfaces

• Plasma cutters - used for cutting metal using a plasma torch

• Water jet cutters - used for cutting materials using a high-pressure jet...read more

Stress strain diagram shows the relationship between stress and strain in a material.

• Stress strain diagram is a graphical representation of the relationship between stress (force per unit area) and strain (deformation) in a material.

• It helps engineers understand the mechanical properties of materials, such as elasticity, yield strength, and ultimate strength.

• The diagram typically consists of a linear elastic region, a yield point, a plastic deformation region, and a fracture ...read more

Some manufacturing processes include casting, machining, welding, and 3D printing.

• Casting: involves pouring molten metal into a mold to create a specific shape

• Machining: involves removing material from a workpiece to achieve the desired shape and size

• Welding: involves joining two or more pieces of metal together using heat and pressure

• 3D printing: involves creating a three-dimensional object by layering material based on a digital model

Supply and demand is the relationship between the availability of a product or service and the desire for that product or service in the market.

• Supply refers to the amount of a product or service that is available for purchase.

• Demand refers to the desire or need for a product or service in the market.

• When supply is high and demand is low, prices tend to decrease. When supply is low and demand is high, prices tend to increase.

• Supply and demand interact to determine the equilib...read more

Semiconductor is a material that has electrical conductivity between a conductor and an insulator.

• Semiconductors are used in electronic devices like transistors, diodes, and integrated circuits.

• They have a band gap that allows them to conduct electricity under certain conditions.

• Common semiconductor materials include silicon, germanium, and gallium arsenide.

Bearings are mechanical components that allow for smooth rotation or linear motion between two parts.

• Bearings reduce friction between moving parts

• They support radial and axial loads

• Common types include ball bearings, roller bearings, and plain bearings

• Bearings are used in various applications such as automotive, aerospace, and industrial machinery

Belt conveyor design involves determining the belt width, speed, and type, as well as the conveyor length and support structure.

• Determine the material to be conveyed and its characteristics

• Calculate the required belt width and speed based on material flow rate

• Select the appropriate belt type based on material properties and operating conditions

• Design the conveyor length and support structure based on site constraints and material handling requirements

Pumps are devices used to move fluids from one place to another. There are various types of pumps based on their working principle and application.

• Centrifugal pumps: use rotating impeller to increase fluid velocity and pressure

• Reciprocating pumps: use piston or diaphragm to create pressure

• Gear pumps: use interlocking gears to move fluid

• Peristaltic pumps: use rollers to squeeze fluid through a tube

• Diaphragm pumps: use flexible diaphragm to move fluid

There are seven basic logic gates: AND, OR, NOT, NAND, NOR, XOR, and XNOR.

• AND gate: outputs true only if both inputs are true (1 AND 1 = 1, 0 AND 1 = 0, etc.)

• OR gate: outputs true if at least one input is true (1 OR 0 = 1, 0 OR 0 = 0, etc.)

• NOT gate: inverts the input (NOT 1 = 0, NOT 0 = 1)

• NAND gate: combination of AND gate followed by NOT gate

• NOR gate: combination of OR gate followed by NOT gate

• XOR gate: outputs true if exactly one input is true (1 XOR 0 = 1, 0 XOR 1 = 1, etc...read more

Property of Inertia is the tendency of an object to resist changes in its state of motion.

• Inertia is a property of matter that causes an object to resist changes in its motion.

• Objects at rest tend to stay at rest, while objects in motion tend to stay in motion.

• The greater the mass of an object, the greater its inertia.

• Examples include a heavy truck being harder to stop than a bicycle due to its greater inertia.

My favorite subject is Thermodynamics.

• I find Thermodynamics fascinating because it deals with the study of energy and its transformations.

• I enjoy learning about the laws of thermodynamics and how they apply to various systems.

• Thermodynamics plays a crucial role in mechanical engineering, especially in areas like heat transfer and energy conversion.

• I have worked on projects involving thermodynamic analysis, such as designing efficient cooling systems for engines.

• Understanding ...read more