70+ Assistant Electrical Engineer Interview Questions and Answers

Planning and executing a 1 KM 11KV transmission line requires careful consideration of various factors.

• Conduct a site survey to determine the route and identify any obstacles

• Design the transmission line based on the load requirements and voltage drop calculations

• Obtain necessary permits and approvals from local authorities

• Procure materials and equipment required for construction

• Ensure safety measures are in place during construction

• Test and commission the transmission line be...read more

To communicate between multiple Mitsubishi PLCs, use the ladder programming language and establish a network connection.

• Use the GX Works2 software to program the Mitsubishi PLCs

• Configure the network settings on each PLC to establish a network connection

• Assign unique IP addresses to each PLC

• Use the Ethernet communication protocol to exchange data between PLCs

• Implement ladder logic instructions to send and receive data between PLCs

• Use communication modules or special function b...read more

IMCC panels are used for motor control and automation. 800A MCC panel requires specific switchgear and has a fault level in the busbars.

• IMCC panels are used for motor control and automation in industrial settings

• 800A MCC panel requires specific switchgear such as circuit breakers and fuses

• The fault level for 800A MCC panel in the busbars depends on the system voltage and impedance

• PLC and automation systems are used to control and monitor the IMCC panels

• PLC programming involve...read more

The installation process for a 100 KVA DTR involves site preparation, foundation construction, equipment placement, wiring, and testing.

• Prepare the site by clearing the area and ensuring proper drainage

• Construct a foundation that is level and able to support the weight of the DTR

• Place the DTR on the foundation and secure it in place

• Connect the wiring according to the manufacturer's instructions

• Test the DTR to ensure it is functioning properly

MCB, MCCB, RCB, load calculation, motor selection criteria, induction motor, field devices

• MCB stands for Miniature Circuit Breaker, used for protecting electrical circuits from overcurrent

• MCCB stands for Molded Case Circuit Breaker, used for higher current ratings and protection

• RCB stands for Residual Current Breaker, used for protection against electric shock

• Load calculation involves determining the electrical load requirements for a specific system or equipment

• Motor selecti...read more

PPE stands for Personal Protective Equipment. Building a safety work culture involves training, communication, enforcement, and leading by example.

• PPE includes items like helmets, gloves, goggles, and safety shoes to protect workers from hazards.

• Conduct regular safety training sessions to educate employees on the importance of using PPE.

• Communicate safety protocols clearly and consistently to all employees.

• Enforce safety policies and procedures to ensure compliance.

• Lead by ex...read more

Transformers breathe through cooling systems and use materials like oil or air for insulation.

• Transformers have cooling systems to dissipate heat generated during operation.

• The cooling system can be either oil-based or air-based.

• Oil-filled transformers use oil as a cooling and insulating medium.

• Air-cooled transformers use fans or radiators to cool the windings.

• The cooling system ensures the transformer operates within safe temperature limits.

PF is power factor, a measure of how efficiently electrical power is being used. A capacitor is an electrical component that stores energy. A capacitor bank is a group of capacitors connected together to improve power factor.

• Power factor (PF) is the ratio of real power to apparent power in an AC circuit.

• A capacitor is an electrical component that stores energy in an electric field.

• A capacitor bank is a group of capacitors connected together to improve power factor by reducing...read more

Voltage regulation is the process of maintaining a stable voltage level at the distribution level.

• Voltage regulation is achieved by using transformers and voltage regulators to adjust the voltage as needed.

• Voltage regulators can be either tap-changing transformers or electronic devices that adjust the voltage automatically.

• By monitoring the voltage levels and making adjustments as necessary, the desired voltage is maintained at the distribution level.

• Voltage regulation is imp...read more

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

• Transformers work on the principle of electromagnetic induction

• They have two coils, primary and secondary, wound around a common magnetic core

• When an alternating current flows through the primary coil, it creates a magnetic field which induces a voltage in the secondary coil

• The voltage in the secondary coil is proportional to the number of turns...read more

Different types of Earthings include: protective earthing, functional earthing, system earthing, and lightning earthing.

• Protective earthing is used to prevent electric shock and ensure safety.

• Functional earthing is used to provide a reference potential for electrical equipment.

• System earthing is used to stabilize voltage levels and protect against faults.

• Lightning earthing is used to protect structures from lightning strikes.

• Other types of earthing include signal earthing, in...read more

The size of cable used for a 1 ton AC depends on various factors such as voltage, current, and distance.

• The cable size is determined by the current rating of the AC unit.

• For a 1 ton AC, the current rating is typically around 5-7 amps.

• The cable size can be calculated using the current carrying capacity of the cable and the voltage drop considerations.

• Factors like the distance between the AC unit and the power source also play a role in determining the cable size.

• Consulting ele...read more

A servo motor is a rotary actuator that allows for precise control of angular position.

• Servo motors are commonly used in robotics, automation, and control systems.

• They consist of a DC motor, a position feedback sensor, and a control circuit.

• The control circuit receives a control signal and adjusts the motor's position accordingly.

• Servo motors can rotate between 0 and 180 degrees, or even continuously in some cases.

• They provide high torque and accurate positioning.

• Modes of com...read more

Transformer oil should be tested for dielectric strength, acidity, water content, and dissolved gas analysis. Significant out gases include methane, ethylene, and acetylene.

• Dielectric strength test measures the ability of the oil to withstand electric stress without breaking down.

• Acidity test determines the level of acidic compounds present in the oil, which can degrade insulation.

• Water content test checks for moisture that can reduce the dielectric strength of the oil.

• Dissol...read more

UPS stands for Uninterruptible Power Supply. The maximum capacity of UPS varies depending on the model and brand.

• UPS stands for Uninterruptible Power Supply

• Maximum capacity of UPS varies depending on model and brand

• Common capacities range from 350VA to 10kVA

• Example: APC Smart-UPS 1500VA has a capacity of 1500VA

Motor working principles involve the interaction between magnetic fields and electric currents to produce rotational motion.

• Electric current is passed through a coil of wire, creating a magnetic field that interacts with the magnetic field of a permanent magnet to produce rotational force.

• The direction of the current determines the direction of the rotation.

• Motor testing involves measuring the motor's performance characteristics such as speed, torque, and efficiency.

• Testing c...read more

Distribution transformers are typically installed in rectangular areas near the load centers for efficient power distribution.

• Distribution transformers are installed in rectangular areas near load centers to step down voltage for distribution to consumers.

• They are usually placed outdoors on concrete pads or inside fenced enclosures for safety and accessibility.

• The location should allow for easy maintenance and access for utility workers.

• Examples of where distribution transfor...read more

Machines ratings are in kVA instead of kW due to the presence of reactive power.

• kVA represents the apparent power of a machine, which includes both real power (kW) and reactive power (kVAR).

• Reactive power is required by machines with inductive or capacitive loads to create magnetic fields or store energy.

• kW represents the actual power consumed or produced by a machine, while kVA represents the total power required to perform work.

• Using kVA ratings helps in sizing electrical e...read more

Sensors include temperature, pressure, proximity, light, and motion sensors. Timers include programmable, countdown, and interval timers.

• Temperature sensors measure the temperature of an object or environment

• Pressure sensors measure the pressure of a fluid or gas

• Proximity sensors detect the presence of nearby objects

• Light sensors measure the intensity of light

• Motion sensors detect movement

• Programmable timers can be set to turn on or off at specific times

• Countdown timers count...read more

The size of cable is selected based on factors like current carrying capacity, voltage drop, and environmental conditions.

• Consider the current carrying capacity of the cable, which depends on the load and the type of cable.

• Calculate the voltage drop to ensure it is within acceptable limits.

• Take into account the environmental conditions such as temperature, moisture, and chemical exposure.

• Refer to relevant standards and codes for guidance on cable sizing.

• Consider future expans...read more

A soft starter is a device used to gradually start and control the speed of an electric motor.

• Soft starters are used to reduce the mechanical stress on motors during startup.

• They provide a gradual increase in voltage to the motor, preventing sudden surges.

• Soft starters can also control the acceleration and deceleration of the motor.

• They are commonly used in applications where a smooth and controlled startup is required, such as conveyor belts or pumps.

• Example: A soft starter ...read more

Parameters for synchronisation of DG set to bus bar

• Frequency matching between DG set and bus bar

• Voltage matching between DG set and bus bar

• Phase sequence matching between DG set and bus bar

• Synchronisation panel settings

• Proper earthing and grounding

• Load sharing and load transfer

• Protection and safety measures

RTD and TC are used for temperature measurement in various industries.

• RTD stands for Resistance Temperature Detector and TC stands for Thermocouple.

• RTD measures temperature by sensing the change in resistance of a metal wire as temperature changes.

• TC measures temperature by sensing the voltage generated by the junction of two dissimilar metals.

• RTD is more accurate and stable than TC, but TC is more rugged and can measure higher temperatures.

• RTD is commonly used in industries ...read more

Single phase machines are designed by using a single phase power supply and incorporating specific design elements.

• Single phase machines use a single phase power supply, typically from a residential or commercial electrical system.

• They are designed with specific components such as a single phase winding, a capacitor for starting, and a centrifugal switch for switching between starting and running modes.

• Examples of single phase machines include single phase induction motors, s...read more

HG fuse is a high-grade fuse used in electrical systems to protect against overcurrents.

• HG fuse stands for High-Grade fuse.

• It is used in electrical systems to protect against overcurrents.

• It works by melting a fuse element when excessive current flows through it.

• The melting of the fuse element breaks the circuit and prevents damage to the electrical system.

• HG fuses are commonly used in industrial applications and power distribution systems.

My favorite subject in engineering is power systems.

• I enjoy learning about the generation, transmission, and distribution of electrical power.

• I find it fascinating how power systems are designed to ensure reliable and efficient delivery of electricity.

• I am particularly interested in renewable energy sources and their integration into power systems.

• I have taken courses in power systems analysis, power electronics, and renewable energy systems.

• I have also completed projects rel...read more

Earthing is a process of connecting electrical equipment to the ground to prevent electric shock and protect against electrical faults.

• Earthing is done by connecting the electrical equipment to a conductive material, such as a metal rod, buried in the ground.

• The purpose of earthing is to provide a path for the flow of excess electrical current to the ground, preventing damage to the equipment and ensuring safety.

• Earthing helps in dissipating static electricity and reducing el...read more

VFD stands for Variable Frequency Drive. It is a type of motor controller that drives an electric motor by varying the frequency and voltage supplied to the motor.

• VFD controls the speed and torque of an AC motor by varying the frequency of the electrical supply to the motor.

• It converts fixed frequency and voltage AC power to variable frequency and voltage output.

• VFDs are commonly used in HVAC systems, pumps, conveyors, and other industrial applications.

• The working principle i...read more

Line capacitance in transmission lines provides several advantages.

• Improves power factor by compensating for inductive reactance

• Reduces voltage drop and improves voltage regulation

• Enhances stability and reduces the risk of voltage collapse

• Enables efficient power transfer over long distances

• Helps in reducing electromagnetic interference (EMI)

• Allows for the use of higher transmission voltages

PLC stands for Programmable Logic Controller. It is an industrial computer used to automate processes and control machinery.

• PLCs are used in manufacturing, transportation, and energy industries

• They are programmed using ladder logic or other programming languages

• PLCs can monitor inputs from sensors and control outputs to actuators

• They are designed to be rugged and reliable in harsh industrial environments

Reactive power can be maintained by using power factor correction techniques.

• Install power factor correction capacitors to offset the reactive power.

• Use synchronous condensers to generate or absorb reactive power as needed.

• Implement voltage control measures to regulate reactive power flow.

• Optimize system design and equipment selection to minimize reactive power losses.

• Regularly monitor and maintain power factor to ensure efficient reactive power management.

Drive is a device used to control the speed and torque of an electric motor. Maintenance involves regular inspection, cleaning, and lubrication.

• Drive is a device that regulates the speed and torque of an electric motor

• Maintenance includes regular inspection to check for wear and tear

• Cleaning the drive components to remove dust and debris

• Lubricating moving parts to ensure smooth operation

• Replacing any faulty components to prevent breakdowns

• Examples: Variable Frequency Drives (...read more

To reduce count of burnt DTR, proper maintenance, regular inspections, and timely replacements are essential.

• Regularly inspect DTRs for any signs of overheating or damage

• Ensure proper ventilation and cooling systems are in place

• Implement regular maintenance schedules for cleaning and testing

• Replace old or faulty components before they cause damage

• Train staff on proper handling and maintenance procedures

Backless is a term used in electrical engineering to describe a device or equipment that does not have a back or rear panel.

• Backless devices are typically designed for easy access and maintenance.

• They may have open or exposed components on the back side.

• Examples of backless devices include open-frame power supplies and certain types of circuit boards.

• Backless equipment may require additional safety precautions due to the exposed components.

• Backless designs are often used in a...read more

APFC (Automatic Power Factor Correction) capacitor banks are used to improve power factor and reduce reactive power consumption in electrical systems.

• Improves power factor by reducing reactive power consumption

• Helps in reducing electricity bills by avoiding penalties for low power factor

• Increases efficiency of electrical systems by reducing losses

• Extends the life of electrical equipment by reducing stress on the system

• Ensures stable voltage levels and reduces voltage fluctuat...read more

Insulators are materials used to prevent the flow of electricity. They must have high resistivity, mechanical strength, and thermal stability.

• Types of insulators include porcelain, glass, polymer, and ceramic.

• Requirements for insulators include high resistivity to prevent leakage current, mechanical strength to withstand mechanical stress, and thermal stability to withstand temperature variations.

• Examples of insulators include suspension insulators used in overhead power line...read more

CT/PT are used in electrical systems to measure and protect against high currents and voltages.

• CT (Current Transformer) is used to measure high currents and step them down to a manageable level for measurement or protection devices.

• PT (Potential Transformer) is used to measure high voltages and step them down to a safe level for measurement or protection devices.

• CTs and PTs are commonly used in power systems, electrical substations, and industrial applications.

• CTs and PTs pro...read more

Primary winding receives electrical energy from the source while secondary winding delivers the transformed energy to the load.

• Primary winding is connected to the input voltage source

• Secondary winding is connected to the load

• Primary winding has fewer turns than secondary winding to step up voltage

• Secondary winding has more turns than primary winding to step down voltage

The size of cable needed for a 1 Ton AC depends on the current rating and distance of the cable run.

• The size of cable should be selected based on the current rating of the AC unit and the distance the cable needs to run.

• Typically, a 1 Ton AC unit would require a cable size of 1.5mm² to 2.5mm² for a short distance.

• For longer distances, a larger cable size may be needed to account for voltage drop.

• Consult a qualified electrician or refer to the manufacturer's guidelines for the...read more

A program to add two numbers.

• Declare two variables to store the numbers

• Take input from user for both variables

• Add the two variables and store the result in a third variable

• Print the result

Wind turbines convert the kinetic energy of the wind into mechanical power, which is then converted into electricity.

• Wind turns the blades of the turbine

• Blades are connected to a rotor

• Rotor spins a generator to produce electricity

• Electricity is then sent to the grid for distribution

There are various types of motors such as AC motors, DC motors, stepper motors, servo motors, etc.

• AC motors: used for high power applications

• DC motors: used for low power applications

• Stepper motors: used for precise positioning

• Servo motors: used for control systems

• Brushless DC motors: used for high efficiency and low maintenance

• Induction motors: used for industrial applications

• Linear motors: used for linear motion

• Synchronous motors: used for constant speed applications

A signal line diagram of a substation is a schematic representation of the electrical connections and components within the substation.

• It shows the interconnection between various devices such as transformers, circuit breakers, relays, and meters.

• The diagram includes details of control circuits, protection systems, and communication networks within the substation.

• Signal line diagrams help in understanding the flow of signals and control commands within the substation.

• They are...read more

Yes, I am adaptable to West Bengal.

• I have lived in different parts of India and have experience adapting to new cultures and environments.

• I am willing to learn about the local customs and traditions of West Bengal.

• I am excited about the opportunity to work in West Bengal and contribute to the development of the region.

• I am open to exploring new places and trying new things, which will help me adapt to the local lifestyle.

• I am confident that I can adjust to the climate and oth...read more

Substation structure for a 33kV line includes equipment such as transformers, circuit breakers, isolators, and lightning arresters.

• Substation must have transformers to step down voltage from 33kV to lower levels for distribution.

• Circuit breakers are used to protect the system from overloads and short circuits.

• Isolators are used for isolating equipment for maintenance purposes.

• Lightning arresters protect the equipment from lightning strikes.

• Substation structure must be designe...read more

Types of generators include diesel, gas, and wind generators. Types of circuit breakers include air, oil, and vacuum circuit breakers.

• Types of generators: diesel, gas, wind

• Types of circuit breakers: air, oil, vacuum

I am currently earning X and expecting Y for the Assistant Electrical Engineer position.

• My current annual CTC is X.

• For the Assistant Electrical Engineer position, I am expecting a CTC of Y.

• I am open to negotiation based on the company's policies and the job responsibilities.

• I am looking for a fair compensation package that aligns with my skills and experience.