900+ Mechanical Engineer Interview Questions and Answers

A diesel generator works by converting diesel fuel into mechanical energy which is then converted into electrical energy.

• Diesel fuel is injected into the combustion chamber where it ignites and creates high pressure gases that push the piston down, creating mechanical energy.

• The mechanical energy is then converted into electrical energy through the use of an alternator.

• The alternator uses a magnetic field and a conductor to generate an electrical current.

• The electrical curren...read more

Lubrication is necessary for smooth functioning of equipment. Different types of equipment require different lubrication methods.

• Equipment with moving parts require lubrication to reduce friction and wear.

• Oil or grease can be used as lubricants depending on the equipment.

• Lubrication intervals should be followed as per manufacturer's recommendations.

• Examples of equipment that require lubrication include engines, pumps, bearings, and gears.

NGK spark plugs are used in Maruti Suzuki cars.

• Maruti Suzuki uses NGK spark plugs in their cars.

• NGK is a popular brand of spark plugs known for their quality and durability.

• NGK spark plugs are designed to improve fuel efficiency and reduce emissions.

• Other car manufacturers also use NGK spark plugs in their vehicles.

Pascal's law states that pressure applied to a fluid is transmitted equally in all directions. Entropy is a measure of disorder or randomness in a system.

• Pascal's law is important in hydraulic systems, where pressure is used to transmit force.

• Entropy is a thermodynamic property that increases with the degree of disorder in a system.

• Entropy can be used to predict the direction of chemical reactions and the efficiency of energy conversion processes.

To identify problems in gearbox, fans, and blowers, one can perform visual inspections, listen for abnormal noises, check for vibrations, monitor temperature, and conduct performance tests.

• Perform visual inspections to check for any signs of wear, damage, or leaks.

• Listen for abnormal noises such as grinding, rattling, or whining sounds.

• Check for vibrations in the gearbox, fans, or blowers, which may indicate misalignment or imbalance.

• Monitor temperature levels to ensure they ...read more

Different types of pumps include centrifugal, positive displacement, and axial flow. Sealing systems include mechanical, gland, and magnetic.

• Centrifugal pumps use a rotating impeller to create a flow of fluid. Examples include end-suction, inline, and multistage pumps.

• Positive displacement pumps move fluid by trapping a fixed amount and forcing it through the discharge. Examples include piston, diaphragm, and gear pumps.

• Axial flow pumps move fluid parallel to the axis of rota...read more

Inspection is a thorough examination or assessment of a building or equipment to ensure safety and compliance with regulations.

• Inspections involve checking for potential hazards, defects, or violations of codes and standards.

• Inspectors may use tools such as cameras, measuring devices, or testing equipment during the inspection.

• The purpose of an inspection is to identify and address any issues that could pose a risk to safety or health.

• Examples of inspections include fire safe...read more

Pumps are used to transfer fluids from one place to another, while turbines convert fluid energy into mechanical energy.

• Pumps are used in various applications such as water supply, irrigation, and oil refineries.

• Turbines are commonly used in power generation plants to convert the energy of flowing water, steam, or gas into mechanical energy.

• Pumps and turbines are both types of machines that involve the movement of fluids.

• Pumps generally increase the pressure of the fluid, whi...read more

The theory of failure suitable for ductile materials is the Von Mises criterion, and for brittle materials, it is the Maximum Principal Stress theory.

• Ductile materials undergo plastic deformation before failure, so the Von Mises criterion, which considers the yield strength of the material, is suitable.

• Brittle materials fail suddenly without any plastic deformation, so the Maximum Principal Stress theory, which considers the tensile strength of the material, is suitable.

• Examp...read more

Measure 4 liters using a 5-liter and a 3-liter tank through strategic filling and pouring.

• Fill the 5-liter tank completely.

• Pour water from the 5-liter tank into the 3-liter tank until the 3-liter tank is full.

• This leaves you with 2 liters in the 5-liter tank.

• Empty the 3-liter tank completely.

• Pour the remaining 2 liters from the 5-liter tank into the 3-liter tank.

• Now fill the 5-liter tank again completely.

• Pour water from the 5-liter tank into the 3-liter tank until it is full ...read more

Adiabatic process is a thermodynamic process where no heat is exchanged with the surroundings. Hyperbolic process is a type of adiabatic process.

• Adiabatic process occurs when there is no heat transfer between the system and its surroundings

• Hyperbolic process is a type of adiabatic process where the pressure and volume of a gas are inversely proportional

• Adiabatic compression of a gas can cause an increase in temperature

• Adiabatic expansion of a gas can cause a decrease in tempe...read more

To identify a problem in a running machine bearing, one can listen for abnormal noises, check for excessive vibration, monitor temperature, and inspect for wear or damage.

• Listen for abnormal noises such as grinding, squeaking, or knocking sounds.

• Check for excessive vibration in the machine or bearing housing.

• Monitor the temperature of the bearing using an infrared thermometer or thermal imaging camera.

• Inspect the bearing for signs of wear, such as pitting, scoring, or discolo...read more

Quality Control (QC) involves a series of steps to ensure products meet quality standards.

• 1. Establish quality standards and specifications for the product.

• 2. Create a quality control plan outlining inspection procedures and criteria.

• 3. Perform inspections and tests during production to identify defects.

• 4. Implement corrective actions to address any issues found.

• 5. Monitor and evaluate the effectiveness of the quality control process.

• 6. Document all quality control activities...read more

The engine oil capacity varies depending on the make and model of the vehicle.

• Engine oil capacity can be found in the owner's manual or by contacting the manufacturer.

• It is important to use the correct amount of oil to ensure proper lubrication and prevent damage to the engine.

• Overfilling or underfilling the oil can lead to engine problems.

• Some vehicles may require more oil for larger engines or for towing purposes.

Centrifugal pump suction is positive.

• Centrifugal pumps work by creating a low pressure at the inlet or suction side of the pump.

• This low pressure causes the fluid to flow into the pump.

• The suction pressure is always lower than the discharge pressure.

• The suction pressure can be measured using a pressure gauge.

• Positive suction pressure is required for the pump to work properly.

20 alternative uses of a stapler

• As a makeshift hole puncher

• To hold together a broken necklace chain

• To create a makeshift zipper pull

• To create a makeshift lock for a door

• To create a makeshift weight for a fishing line

• To create a makeshift needle for sewing

• To create a makeshift screwdriver

• To create a makeshift zipper repair tool

• To create a makeshift paper clip

• To create a makeshift zipper stopper

• To create a makeshift zipper slider

• To create a makeshift zipper puller

• To create a ma...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.

Effective DFM and DFA ensure efficient production and assembly, while material selection and prioritization are crucial for project success.

• DFM Principles: I focus on simplifying designs by minimizing part count and using standard components, which reduces manufacturing complexity.

• DFA Techniques: I utilize assembly jigs and fixtures to streamline the assembly process, ensuring parts fit together easily and accurately.

• Material Selection: For lightweight yet strong components, ...read more

Expected CTC should be discussed during the interview process.

• It is important to research industry standards and company salary ranges before giving a number.

• Consider the job responsibilities, experience, and qualifications when determining expected CTC.

• Be open to negotiation and understand the company's benefits package.

• Avoid giving a specific number too early in the interview process.

• Instead, ask about the company's salary range and discuss expectations.

• Example: Based on my...read more

The Pacific Ocean is the largest ocean in the world.

• The Pacific Ocean covers an area of about 63 million square miles.

• It is larger than all the other oceans combined.

• It stretches from the Arctic Ocean in the north to the Southern Ocean in the south.

• The Pacific Ocean is home to numerous islands, including Hawaii and Easter Island.

IDU and ODU are abbreviations used in air conditioning systems. IDU stands for Indoor Unit and ODU stands for Outdoor Unit.

• IDU is the unit that is installed inside the room or building, while ODU is installed outside.

• IDU is responsible for cooling or heating the air inside the room, while ODU is responsible for dissipating the heat outside.

• IDU is connected to ODU through refrigerant pipes and electrical cables.

• Examples of IDU include wall-mounted units, ceiling cassette units...read more

During zero break in the plant, we perform routine maintenance tasks and inspections to ensure smooth operations.

• Performing equipment checks and maintenance

• Inspecting and repairing any mechanical issues

• Calibrating and adjusting machinery

• Conducting preventive maintenance

• Updating maintenance logs and documentation

Couplings are used to connect two shafts together. The type of coupling used depends on the application.

• Flexible couplings are used to compensate for misalignment between shafts.

• Rigid couplings are used when shafts are perfectly aligned.

• Gear couplings are used for high torque applications.

• Jaw couplings are used for low to medium torque applications.

• Disc couplings are used for high-speed applications.

• Chain couplings are used for applications with large distances between shafts...read more

In a high-pressure situation, prioritizing health and efficiency is key. Taking a brief break can enhance overall productivity.

• Take a 1-minute break to hydrate and refuel, which can improve focus and efficiency.

• Consider quick snacks like nuts or a protein bar that can be consumed easily.

• Set a timer for 1 minute to ensure you return to work promptly after the break.

• Use this break to stretch and refresh your mind, which can lead to better problem-solving.

• If possible, delegate m...read more

Duplex stainless steel is good for NaCl 2500 ppm fluid due to its high corrosion resistance and strength.

• Duplex stainless steel has a high resistance to corrosion and pitting

• It has a high strength and toughness

• Other materials like carbon steel and copper alloys may corrode in NaCl solutions

I may have theoretical knowledge only, but I am a quick learner and willing to work hard to gain practical experience.

• I am eager to learn and willing to put in extra effort to gain practical experience.

• I have a strong foundation in theoretical knowledge, which can be applied to real-world situations.

• I am a quick learner and can adapt to new situations easily.

• I am open to feedback and willing to learn from my mistakes.

• I am a team player and can work collaboratively with experi...read more

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