40+ R Mehra & Co Interview Questions and Answers

The thyristor value from gate to cathode in an induction furnace depends on the specific design and requirements of the furnace.

• The thyristor value is determined by the voltage and current ratings required for the induction furnace.

• It is important to select a thyristor with appropriate voltage and current handling capabilities to ensure reliable operation.

• The thyristor value may vary depending on the power rating and frequency of the induction furnace.

• Consulting the furnace's...read more

Over current in furnace is mainly caused by short circuits or overload.

• Short circuits

• Overload

• Faulty wiring

• Malfunctioning equipment

Transformers used in furnaces are mainly of two types - power transformers and isolation transformers.

• Power transformers are used to step down the high voltage power supply to a lower voltage suitable for the furnace.

• Isolation transformers are used to isolate the furnace from the power supply to prevent electrical interference.

• Other types of transformers used in furnaces include control transformers and potential transformers.

• Control transformers are used to power the control...read more

Slip ring motor has external connections for rotor winding while 3 phase induction motor has a squirrel cage rotor.

• Slip ring motor has external connections for rotor winding, allowing for external control of rotor circuit.

• 3 phase induction motor has a squirrel cage rotor, which is simpler and more rugged.

• Slip ring motor is used in applications where variable speed control is required, such as cranes and hoists.

• 3 phase induction motor is commonly used in industrial application...read more

Steel is an alloy of iron and carbon. It is made through various processes like Bessemer, Open Hearth, and Electric Arc Furnace.

• Steel is a metal alloy made by combining iron and carbon.

• There are different types of steel such as carbon steel, alloy steel, stainless steel, etc.

• The making process of steel involves melting iron ore and adding carbon to it.

• The Bessemer process, Open Hearth process, and Electric Arc Furnace process are some of the methods used to make steel.

• Steel i...read more

Hydraulic systems use liquid to transmit power, while pneumatic systems use compressed air.

• Hydraulic systems use incompressible fluids like oil or water, while pneumatic systems use compressed air or gas.

• Hydraulic systems can generate higher forces and are used in heavy machinery like cranes and excavators.

• Pneumatic systems are lighter and more flexible, commonly used in applications like air brakes in vehicles.

• Hydraulic systems are generally more expensive and require more m...read more

Standard procedures for UT, tensile and impact testing

• UT testing follows ASTM E164 standards

• Tensile testing follows ASTM E8 standards

• Impact testing follows ASTM E23 standards

• Work instructions should include equipment calibration, sample preparation, and testing procedures

• Documentation of results and analysis should be included in the work instructions

Yield is the amount of product obtained in a chemical reaction or manufacturing process.

• Yield is expressed as a percentage of the theoretical maximum amount of product that could be obtained.

• Factors that can affect yield include reaction conditions, purity of reactants, and the efficiency of the manufacturing process.

• For example, if a chemical reaction has a theoretical yield of 100 grams and the actual yield is 80 grams, the yield would be 80%.

I have faced various hydraulic breakdowns in my career as a Mechanical Maintenance Engineer.

• One common hydraulic breakdown is a leak in the hydraulic system, which can be caused by worn-out seals or damaged hoses.

• Another issue is a hydraulic pump failure, which can occur due to excessive wear and tear or lack of proper maintenance.

• Clogged or blocked hydraulic filters can also lead to breakdowns, as they restrict the flow of hydraulic fluid.

• Problems with hydraulic valves, such...read more

OEE stands for Overall Equipment Efficiency.

• OEE is a measure of how effectively a manufacturing operation is utilized

• It takes into account three factors: availability, performance, and quality

• OEE is calculated by multiplying the availability, performance, and quality percentages

• It is commonly used in TPM (Total Productive Maintenance) to assess equipment effectiveness

DC motors use direct current to generate rotational motion, while AC motors use alternating current.

• DC motors have a commutator and brushes to switch the current direction

• AC motors have a stator and rotor to create a rotating magnetic field

• DC motors are commonly used in household appliances and electric vehicles

• AC motors are commonly used in industrial machinery and HVAC systems

Absenteeism can be controlled through various measures such as implementing flexible work schedules, offering incentives for good attendance, and providing a supportive work environment.

• Implement flexible work schedules to accommodate employees' personal needs

• Offer incentives for good attendance such as bonus or extra paid time off

• Provide a supportive work environment where employees feel valued and motivated to come to work

• Track and monitor absenteeism rates to identify patt...read more

A steel plant is a facility where raw materials are transformed into steel products.

• Steel plants typically use iron ore, coal, and limestone as raw materials

• The process involves melting the raw materials in a blast furnace and then refining the molten metal

• The refined steel is then cast into various shapes and sizes for use in construction, manufacturing, and other industries

• Examples of steel products include beams, pipes, wires, and sheets

TPM stands for Trusted Platform Module.

• TPM is a hardware-based security chip that provides secure storage and cryptographic functions.

• It is used to enhance the security of computers and protect sensitive data.

• TPM can be found in many devices such as laptops, desktops, and servers.

• Examples of TPM manufacturers include Infineon, Nuvoton, and STMicroelectronics.

Losses in TPM refer to any reduction in overall equipment effectiveness (OEE) due to various factors.

• Losses can be categorized into three types: availability losses, performance losses, and quality losses.

• Availability losses occur when equipment is not available for production due to breakdowns, changeovers, or planned maintenance.

• Performance losses occur when equipment operates at a slower speed than its maximum capability or experiences minor stoppages.

• Quality losses occur ...read more

Roll cost refers to the expenses associated with the production of rolls, typically in manufacturing or printing industries.

• Roll cost includes the cost of raw materials, labor, equipment, and overhead expenses involved in the production process.

• For example, in a paper manufacturing company, roll cost would include the cost of wood pulp, energy consumption, machine maintenance, and labor wages.

• Roll cost analysis helps in determining the profitability of producing rolls and opt...read more

Metallurgy is the study of physical and chemical behavior of metallic elements, their compounds, and alloys.

• Metallurgy involves studying the properties of metals and their behavior under different conditions.

• It includes processes like extraction, purification, and alloying of metals.

• Metallurgists use techniques like heat treatment, welding, and casting to manipulate metal properties.

• Examples of metallurgical processes include smelting iron ore to produce iron, and tempering s...read more

GSTR-3B is a monthly self-declaration that summarizes all the GST liabilities of a taxpayer.

• GSTR-3B is a summary of all the GST liabilities of a taxpayer for a particular month.

• It includes details of both inward and outward supplies, input tax credit, and tax payable.

• It must be filed by the 20th of the following month.

• TDS stands for Tax Deducted at Source.

• It is a mechanism for collecting tax at the source of income.

• It is applicable to various types of payments such as salary,...read more

Gear, pulley, belt drive, and chain are mechanical components used to transmit motion and power between rotating shafts.

• Gear: Toothed wheel that meshes with another gear to transmit motion.

• Pulley: Wheel with a grooved rim used with a belt to transmit power.

• Belt drive: System of belts and pulleys used to transfer power between shafts.

• Chain: Series of connected links used to transmit motion and power.

• Examples: Gear trains in machinery, pulley systems in elevators, belt drives i...read more

Chemistry 304 and 316 are grades of stainless steel commonly used in various industries.

• 304 stainless steel is a versatile and widely used grade known for its corrosion resistance and durability.

• 316 stainless steel is also corrosion-resistant and has added molybdenum for improved resistance to pitting and crevice corrosion.

• Both grades are commonly used in food processing, pharmaceutical, and chemical industries.

• 304 stainless steel is more affordable than 316, but 316 is often...read more

Attrition can be controlled by improving employee engagement, offering competitive compensation, providing growth opportunities, and conducting exit interviews.

• Improve employee engagement through regular feedback, recognition programs, and career development opportunities.

• Offer competitive compensation and benefits to retain top talent.

• Provide growth opportunities such as training programs, promotions, and cross-functional projects.

• Conduct exit interviews to understand the re...read more

Process control is essential for ensuring consistent quality in manufacturing processes.

• Process control involves monitoring and adjusting variables in a manufacturing process to ensure consistent quality.

• Quality control measures are put in place to ensure that products meet predetermined standards.

• Examples of process control measures include statistical process control, control charts, and process capability analysis.

• Process control is important in industries such as pharmace...read more

Manufacturing processes are methods used to transform raw materials into finished products.

• Casting

• Molding

• Machining

• Joining

• Forming

• Additive manufacturing

Chock overhauling is a process of inspecting, repairing, and maintaining chocks used in various engineering applications.

• Chock overhauling involves disassembling the chock to inspect its components for wear and damage.

• Any worn or damaged parts are repaired or replaced to ensure proper functioning.

• The chock is then reassembled and tested to ensure it meets the required specifications.

• Regular chock overhauling helps prevent breakdowns and ensures the longevity of the equipment....read more

A petrol engine works by igniting a mixture of fuel and air inside a cylinder to create a controlled explosion that powers the engine.

• Fuel and air are mixed in the carburetor or fuel injection system

• The mixture is compressed by a piston inside a cylinder

• A spark plug ignites the mixture, causing a controlled explosion

• The explosion pushes the piston down, which turns the crankshaft and powers the engine

• The exhaust gases are expelled through the exhaust system

To check the motor, you can perform various tests and inspections to ensure it is functioning properly.

• Check for any physical damage or wear on the motor casing

• Inspect the wiring connections for any loose or damaged wires

• Measure the voltage and current going into the motor to ensure it is within the specified range

• Test the motor's insulation resistance to check for any faults

• Run the motor under load to see if it operates smoothly and efficiently

Power analysis involves measuring and analyzing the electrical power consumption of a system or device.

• Identify the components of the system or device that consume power.

• Measure the current and voltage across these components using appropriate instruments.

• Calculate the power consumption using the formula P = VI, where P is power, V is voltage, and I is current.

• Analyze the power consumption data to identify any inefficiencies or areas for improvement.

• Consider factors such as p...read more

Currently overseeing daily operations in retail store

• Managing staff schedules and tasks

• Ensuring inventory levels are maintained

• Handling customer complaints and resolving issues

• Implementing sales strategies to increase revenue

Duty responsibility of a security officer is to ensure safety and security of people and property.

• Patrolling the premises to deter criminal activity

• Monitoring surveillance cameras and alarms

• Responding to emergencies and incidents

• Checking identification and controlling access

• Writing reports and maintaining records

• Cooperating with law enforcement and emergency services

• Providing customer service and assistance

• Enforcing rules and regulations

• Maintaining a professional and alert de...read more

Pillars are vertical structures that provide support and stability to a building or structure.

• Pillars are typically made of strong materials like concrete, steel, or stone.

• They are strategically placed throughout a building to distribute the weight and provide structural integrity.

• Pillars can be decorative elements as well, featuring intricate designs or carvings.

• Examples of famous pillars include the columns of the Parthenon in Athens and the pillars of the Taj Mahal in Indi...read more

5s loss refers to the waste or inefficiency caused by the absence of the 5s principles in a workplace.

• 5s loss is the result of not implementing the 5s principles: Sort, Set in Order, Shine, Standardize, and Sustain.

• It leads to disorganization, wasted time, increased errors, and reduced productivity.

• Examples of 5s loss include searching for tools or materials, cluttered workspaces, and difficulty in finding information or documents.

Diesel engines work by compressing air and fuel in a cylinder, causing combustion and driving a piston.

• Air is drawn into the cylinder and compressed by a piston.

• Fuel is injected into the cylinder and ignites due to the high temperature and pressure.

• The resulting explosion drives the piston, which turns the crankshaft and powers the engine.

• Diesel engines are commonly used in trucks, buses, and heavy equipment due to their high torque and fuel efficiency.

A thyristor is a semiconductor device that acts as a switch and can handle high voltages and currents.

• It has three terminals: anode, cathode, and gate

• It can be turned on by applying a small current to the gate terminal

• It can handle high power and is commonly used in power control applications

• Examples include AC motor speed control, lighting dimming, and power supplies

Electrical safety refers to practices and precautions taken to prevent electrical hazards and accidents.

• Ensuring all electrical equipment is properly maintained and inspected regularly

• Using appropriate personal protective equipment (PPE) when working with electricity

• Following proper lockout/tagout procedures to de-energize equipment before maintenance

• Training employees on electrical safety protocols and procedures

• Implementing ground fault circuit interrupters (GFCIs) in wet o...read more

Motor analysis involves studying the performance, efficiency, and characteristics of electric motors.

• Motor analysis includes evaluating the electrical and mechanical properties of a motor.

• It involves testing the motor under different operating conditions to determine its efficiency and performance.

• Motor analysis helps in identifying any faults or issues in the motor and optimizing its operation.

• Common techniques used in motor analysis include vibration analysis, thermal imagi...read more

TPM stands for Total Productive Maintenance, a system that aims to maximize equipment effectiveness and minimize downtime.

• TPM involves regular maintenance and inspection of equipment

• It focuses on improving overall equipment effectiveness (OEE)

• TPM aims to involve all employees in the maintenance process

• Examples of TPM tools include visual management, autonomous maintenance, and planned maintenance

• TPM can lead to increased productivity, reduced downtime, and improved product qu...read more

A transformer is a device that transfers electrical energy between two or more circuits through electromagnetic induction.

• Transformers are used to increase or decrease voltage levels in electrical circuits.

• They consist of two coils of wire, known as the primary and secondary coils.

• Examples of transformers include power transformers used in electrical substations and voltage transformers in electronic devices.

International trade refers to the exchange of goods and services between countries.

• Involves importing and exporting goods and services across borders

• Facilitates economic growth and development

• Influenced by factors such as tariffs, trade agreements, and currency exchange rates

• Examples include the export of automobiles from Japan to the United States, or the import of coffee from Brazil to Europe

Conference call connection process involves dialing into a designated number and entering a passcode to join the call.

• Dial the designated conference call number provided by the organizer

• Enter the passcode or access code when prompted

• Wait for the host to start the call or for other participants to join

• Mute your microphone when not speaking to avoid background noise

• Use headphones or earphones for better audio quality

TDC stands for Test Design Specification, which outlines the test cases to be executed during testing.

• TDC is a document that details the test cases to be executed during testing.

• It includes information on the test case ID, description, test steps, expected results, and actual results.

• TDC helps ensure that all necessary test cases are executed and documented properly.

• It serves as a reference for testers to follow during the testing process.

• Example: A TDC may include test cases...read more

CNC machines are automated milling machines that can perform various tasks with precision and accuracy.

• Types of CNC machines include milling machines, lathes, plasma cutters, and routers.

• Each type of CNC machine is designed for specific tasks such as cutting, drilling, shaping, and finishing.

• CNC machines can be categorized based on their axis configuration, such as 3-axis, 4-axis, and 5-axis machines.

• Some examples of popular CNC machine brands are Haas, Mazak, and Okuma.