40+ Arkkays National Engineering and Foundry Company Interview Questions and Answers

The tan Delta value of electrical equipment should be as low as possible.

• Tan Delta is a measure of the dielectric losses in electrical equipment.

• A low tan Delta value indicates that the equipment has good insulation properties.

• The tan Delta value can be affected by factors such as temperature, moisture, and aging of the equipment.

• For transformers, a typical tan Delta value is around 0.001 or lower.

The ground clearance of a 400KV transmission line varies depending on various factors.

• The ground clearance of a transmission line is the vertical distance between the lowest point of the conductor and the ground.

• The ground clearance is determined based on safety regulations and requirements.

• Factors that influence the ground clearance include terrain, vegetation, and proximity to buildings or roads.

• In hilly areas, the ground clearance may be higher to account for uneven terrai...read more

Transformers are rated in KVA because it represents the apparent power they can handle.

• KVA stands for kilovolt-ampere, which is a unit of apparent power.

• Transformers are designed to handle a certain amount of power, and the KVA rating indicates their capacity.

• The KVA rating takes into account both the voltage and current that the transformer can handle.

• It helps in determining the appropriate size and capacity of the transformer for a given application.

• For example, a transform...read more

The SF6 gas used for Ckt breaker chamber should be maintained at a pressure of around 5-7 bar.

• The SF6 gas in the circuit breaker chamber should be maintained at a specific pressure to ensure proper functioning.

• The recommended pressure for SF6 gas in the circuit breaker chamber is typically between 5 and 7 bar.

• Maintaining the correct pressure helps in extinguishing the arc during circuit interruption.

• Too low or too high pressure can affect the performance and reliability of th...read more

The Basis setting of REF protection for a transformer should be determined based on the transformer's characteristics and the system requirements.

• The basis setting of REF (Restricted Earth Fault) protection for a transformer is typically determined by considering the transformer's winding configuration, impedance, and the system's fault level.

• The setting should be chosen to ensure that the protection operates reliably for internal faults while avoiding unnecessary tripping fo...read more

ACSRinvar conductors are widely used in metro principal cities due to their high strength and low thermal expansion.

• ACSRinvar conductors have a high tensile strength, making them suitable for long-distance transmission lines in metro cities.

• They have a low coefficient of thermal expansion, which helps in reducing sagging of the conductors and maintaining power transmission efficiency.

• The use of ACSRinvar conductors in metro principal cities ensures reliable and uninterrupted ...read more

AIS and GIS substations differ in their construction and insulation methods.

• AIS (Air Insulated Substation) uses air as the insulation medium, while GIS (Gas Insulated Substation) uses SF6 gas.

• AIS substations require larger land areas compared to GIS substations.

• GIS substations are more compact and can be installed in urban areas where space is limited.

• AIS substations are more susceptible to environmental factors like pollution and weather conditions.

• GIS substations offer high...read more

Star-star zero phase shift transformer windings are used to provide a balanced three-phase output with zero phase shift between primary and secondary voltages.

• Star-star zero phase shift transformer windings are commonly used in power distribution systems.

• They are used to supply power to three-phase loads such as motors, generators, and transformers.

• The windings are designed in such a way that the voltages in the primary and secondary sides are in phase with each other.

• This co...read more

Vibration dampers are used with conductors to reduce the risk of fatigue failure and damage caused by wind-induced vibrations.

• Vibration dampers absorb and dissipate the energy generated by wind-induced vibrations in conductors.

• They help to reduce the risk of fatigue failure and damage to the conductor and associated hardware.

• Vibration dampers are typically installed at regular intervals along the length of the conductor.

• They can be in the form of spiral-shaped devices, weight...read more

The main function of LA in a substation is to protect electrical equipment from lightning strikes.

• LA stands for Lightning Arrester.

• It is installed in substations to divert lightning strikes away from sensitive equipment.

• LA provides a low-impedance path for lightning current to flow to the ground.

• It helps in preventing damage to transformers, circuit breakers, and other electrical devices.

• LA operates by ionizing the air around it, creating a conductive path for lightning curre...read more

When a fan rotates in the opposite direction, it reverses the airflow and can cause the fan to function improperly.

• Reversing the direction of a fan can disrupt the intended airflow in a room.

• In some cases, reversing the fan direction can lead to decreased cooling or heating efficiency.

• Changing the fan direction can also affect the distribution of air in the room.

• For ceiling fans, reversing the direction can change the direction of the downdraft or updraft.

• It is important to c...read more

Stay calm and try to find a way out or signal for help.

• Check for any windows or doors that can be opened

• Try to signal for help by making noise or using a flashlight

• Stay hydrated by drinking any available water

• Stay calm and avoid panic

• If possible, try to contact someone using a mobile phone or other device

Various types of conductors include copper, aluminum, and steel.

• Copper: highly conductive, commonly used in electrical wiring

• Aluminum: lighter and cheaper than copper, used in power lines

• Steel: used in overhead transmission lines for strength and durability

The lines connecting other countries in NER refer to the international borders and transportation routes.

• The international borders of NER connect it with neighboring countries like Bhutan, China, and Myanmar.

• Transportation routes like roads, railways, and airways also connect NER with other countries.

• Examples of transportation routes include the India-Myanmar-Thailand Trilateral Highway and the India-Bhutan Friendship Road.

Power flows from one end to the other through a closed circuit, following the path of least resistance.

• Power flows through conductive materials such as wires or cables.

• It is generated at a power source, such as a generator or a battery.

• The power source creates a potential difference, or voltage, which pushes the electrons to flow.

• The electrons flow from the higher potential end to the lower potential end.

• The flow of electrons creates an electric current.

• The current flows thro...read more

Earthquake effects on structures and design process, including Richter scale and other scales.

• Earthquakes can cause various effects on structures, such as shaking, ground rupture, and liquefaction.

• The design process for structures takes into account the potential seismic forces and aims to ensure safety.

• The Richter scale is a logarithmic scale used to measure the magnitude of an earthquake.

• Other scales used for earthquakes include the moment magnitude scale (Mw) and the modif...read more

PowerGrid is involved in the transmission and distribution of electricity.

• PowerGrid is responsible for the transmission of electricity from power generating stations to distribution substations.

• They also manage the distribution of electricity to end consumers through a network of transmission lines and substations.

• PowerGrid ensures the reliability and stability of the power grid by monitoring and maintaining the transmission infrastructure.

• They play a crucial role in balancin...read more

The formula for I squared R is used to calculate the power dissipated in a resistor.

• I squared R is equal to the current (I) squared multiplied by the resistance (R)

• It is commonly used in electrical engineering to determine the power loss in a resistor

• For example, if the current flowing through a resistor is 2A and the resistance is 5 ohms, the power dissipated can be calculated as (2^2) * 5 = 20 watts

CVT in transmission line works by continuously varying the gear ratio to provide smooth acceleration and optimal engine performance.

• CVT uses a belt and pulley system to vary the gear ratio based on engine speed and load

• It provides seamless acceleration without the need for traditional gear shifts

• CVT allows the engine to operate at its most efficient RPM range for better fuel economy

• Examples of vehicles with CVT include Nissan Altima, Honda Civic, and Subaru Outback

The Indian government typically requires around 1-2 acres of land for setting up a 400kv power transmission line.

• The land requirement for a 400kv power transmission line can vary depending on factors such as terrain, population density, and environmental regulations.

• In general, the Indian government may require anywhere from 1 to 2 acres of land for a 400kv transmission line.

• The exact land requirement will be determined through feasibility studies and consultations with local...read more

A rectifier is an electrical device that converts alternating current (AC) to direct current (DC).

• Rectifiers are commonly used in power supplies to convert AC voltage to DC voltage.

• They consist of diodes that allow current to flow in only one direction.

• Rectifiers are used in various applications such as battery charging, electroplating, and welding.

• Examples of rectifiers include half-wave rectifiers, full-wave rectifiers, and bridge rectifiers.

Curing is necessary to maintain moisture in concrete for proper hydration of cement, ensuring strength and durability.

• Curing prevents moisture loss from concrete

• It helps in proper hydration of cement

• Ensures strength and durability of concrete

• Curing can be done by various methods like water curing, steam curing, etc.

Transmission line is a medium that carries electrical energy from one point to another. There are two types: overhead and underground.

• Transmission line is used to transmit electrical energy from power plants to substations and then to homes and businesses.

• Overhead transmission lines are supported by towers or poles and are visible above ground.

• Underground transmission lines are buried underground and are not visible.

• Overhead transmission lines are cheaper to install but are m...read more

The ground clearing distance of 220 kv lines is typically around 7 meters.

• Ground clearing distance is the minimum distance required between the lowest point of the conductor and the ground.

• For 220 kv lines, the ground clearing distance is usually around 7 meters to ensure safety and prevent any contact with the ground.

• This distance may vary depending on factors such as terrain, local regulations, and specific design considerations.

Distribution refers to the delivery of electricity from high voltage transmission lines to individual customers. Transmission refers to the movement of electricity over long distances from power plants to substations.

• Distribution involves the delivery of electricity to individual customers through a network of power lines and transformers.

• Transmission involves the movement of electricity over long distances from power plants to substations through high voltage transmission li...read more

A power system is a network of electrical components used to generate, transmit, and distribute electrical power.

• Power systems consist of power plants, transformers, transmission lines, and distribution networks.

• They are designed to deliver electricity from power plants to consumers.

• Power systems can be categorized into three main types: generation, transmission, and distribution.

• Examples of power systems include the electrical grid, solar power plants, and wind farms.

Transformer works on the principle of electromagnetic induction to transfer electrical energy between two or more circuits.

• Transformers have two coils of wire, known as primary and secondary coils.

• When an alternating current flows through the primary coil, it creates a changing magnetic field.

• This changing magnetic field induces a voltage in the secondary coil, transferring electrical energy.

• Transformers are used to step up or step down voltage levels in power distribution sy...read more

A ht line is a term commonly used in electrical engineering to refer to a high tension line.

• A ht line is also known as a high voltage line or a transmission line.

• It is used to transmit electricity over long distances.

• These lines are typically made of conductive materials like aluminum or copper.

• Ht lines are supported by tall towers or poles to keep them elevated and away from the ground.

• Examples of ht lines include the power lines you see running across large fields or along ...read more

PRV stands for Pressure Relief Valve, a safety device designed to protect equipment from overpressure by releasing excess pressure.

• PRVs are commonly used in industries such as oil and gas, chemical, and manufacturing.

• They are designed to open when the pressure inside a system exceeds a certain set point, allowing the excess pressure to be released.

• PRVs help prevent catastrophic failures and protect equipment from damage.

• Examples of PRVs include spring-loaded valves, pilot-ope...read more

Testing of transformer involves various electrical tests to ensure its performance and safety.

• Routine tests include turns ratio test, insulation resistance test, and winding resistance test.

• Type tests include temperature rise test, impulse test, and short circuit test.

• Special tests may include partial discharge test and noise level test.

• Testing is crucial to ensure the transformer meets specifications and standards for efficiency and safety.

• Regular maintenance and testing hel...read more

Construction of 132/33 kv substation involves site selection, design, procurement, installation, and commissioning of equipment.

• Site selection based on factors like proximity to load centers, availability of land, and accessibility

• Design includes layout, electrical system design, and protection system design

• Procurement of equipment like transformers, circuit breakers, and switchgear

• Installation involves civil works, equipment installation, and cable laying

• Commissioning includ...read more

My target is to become a certified electrician and gain experience in the field.

• To become a certified electrician

• To gain experience in the field

• To stay up-to-date with the latest technologies and techniques

• To provide excellent service to clients

• To work on challenging projects and expand my skills

A transformer is an electrical device that transfers electrical energy from one circuit to another through electromagnetic induction.

• Transformers are used to increase or decrease the voltage of an alternating current (AC) power supply.

• They consist of two coils of wire, called the primary and secondary, wrapped around a magnetic core.

• When an AC current flows through the primary coil, it creates a magnetic field that induces a voltage in the secondary coil.

• Transformers are used...read more

Buchholz relay is a protective device used in oil-filled transformers to detect and prevent faults.

• It is installed between the transformer tank and conservator tank.

• It detects the presence of gas or oil flow in the transformer oil.

• It operates on the principle of gas collection and oil surge.

• It sends an alarm signal to the control room in case of any fault.

• It helps in preventing major faults and damage to the transformer.

Service tax has been replaced by GST since July 2017. NPV is still relevant for investment decisions.

• Service tax has been subsumed under GST since July 2017

• NPV stands for Net Present Value and is used to evaluate investment decisions

• NPV takes into account the time value of money and calculates the present value of future cash flows

• NPV is still relevant and widely used in finance and investment analysis

La is the chemical symbol for the element Lanthanum, a soft, silvery-white metal.

• Lanthanum is a rare earth element found in minerals such as monazite and bastnasite.

• It has various applications in industries such as electronics, lighting, and camera lenses.

• Lanthanum carbonate is used as a medication to treat high levels of phosphate in the blood of patients with kidney disease.

• It was first discovered in 1839 by Swedish chemist Carl Gustav Mosander.

• Lanthanum has a relatively lo...read more

A wave trap is a device used in electrical systems to filter out unwanted high-frequency signals.

• Wave traps are typically used in power systems to prevent high-frequency currents from flowing back into the system.

• They are designed to have a high impedance at the frequency of the unwanted signal, effectively blocking it from passing through.

• Wave traps can be installed on transmission lines or connected to transformers to protect equipment from damage caused by high-frequency d...read more

Power Grid Corporation of India Limited (PGCIL) is a state-owned electric utility company.

• PGCIL is responsible for the transmission of power across India.

• It was established in 1989 and is headquartered in Gurgaon, Haryana.

• PGCIL operates and maintains over 1,50,000 circuit kilometers of transmission lines.

• It also operates over 238 substations and has a total transformation capacity of over 3,50,000 MVA.

• PGCIL plays a crucial role in ensuring uninterrupted power supply to the co...read more

The height of a 400 kV, 132 kV tower is typically around 25-30 meters.

• The height of a 400 kV, 132 kV tower can vary depending on the design and location.

• Generally, these towers are around 25-30 meters tall to support the transmission lines.

• Factors such as terrain, span length, and voltage level can also influence the tower height.

400 kv hardware detected - need more context to provide answer

• What type of hardware is being referred to?

• What is the context of the detection?

• What are the potential implications of the detection?

• What steps need to be taken next?

The measurement unit of form work is square feet or square meters.

• Form work is the temporary structure used to support concrete until it sets and hardens.

• The measurement of form work is typically done in square feet or square meters.

• The area of the form work is calculated by multiplying the length and width of the form work.

• The measurement of form work is important in determining the amount of materials needed for the project.