100+ Diploma Electrical Engineer Interview Questions and Answers

RBA stands for 'Roller Bearing Assembly'. It is used in rotating machinery to reduce friction and support radial and axial loads.

• RBA is a type of bearing that uses cylindrical rollers instead of balls to reduce friction.

• It is commonly used in heavy-duty applications such as wind turbines, cranes, and mining equipment.

• RBA can support both radial and axial loads, making it ideal for applications where there is both vertical and horizontal movement.

• To use RBA in baring, it shoul...read more

Silica gel is a desiccant commonly used to absorb moisture and prevent the growth of mold and mildew.

• Silica gel is a porous form of silicon dioxide.

• It is often found in small packets or sachets.

• It is used in various industries such as electronics, pharmaceuticals, and food packaging.

• Silica gel can absorb moisture up to 40% of its own weight.

• It is non-toxic and chemically inert.

• Common uses include preserving the freshness of products, protecting electronic devices from moistur...read more

Transformers have two windings, primary and secondary, which are used to transfer electrical energy from one circuit to another.

• Primary winding receives electrical energy from the source

• Secondary winding transfers the electrical energy to the load

• The ratio of turns in the primary and secondary windings determines the voltage transformation

• Transformers can step up or step down voltage levels

• Examples: power transformers, distribution transformers

Handling in construction line involves effective planning, communication, problem-solving, and coordination.

• Develop a detailed project plan and schedule to ensure smooth execution.

• Communicate effectively with team members, contractors, and clients to ensure everyone is on the same page.

• Identify and solve problems promptly to avoid delays and cost overruns.

• Coordinate with different stakeholders, such as architects, engineers, and suppliers, to ensure timely delivery of materia...read more

Different types of diodes include PN junction diode, Zener diode, Schottky diode, Light Emitting Diode (LED), and Photodiode.

• PN junction diode: Basic type of diode used in most electronic circuits.

• Zener diode: Used for voltage regulation and protection against overvoltage.

• Schottky diode: Faster switching speed and lower forward voltage drop compared to PN junction diode.

• Light Emitting Diode (LED): Emits light when current flows through it, used in displays and indicators.

• Phot...read more

A 3 phase transformer is a type of transformer that is designed to handle three-phase power distribution systems.

• Consists of three sets of primary and secondary windings

• Used in power distribution systems to step up or step down voltage in three-phase circuits

• Commonly used in industrial and commercial applications

• Examples include distribution transformers, power transformers, and autotransformers

Rectifier converts AC to DC by allowing current to flow in one direction only.

• Rectifier uses diodes to convert AC to DC.

• Diodes allow current to flow in one direction only.

• Half-wave rectifier uses only one diode while full-wave rectifier uses four diodes.

• Bridge rectifier is a type of full-wave rectifier.

• Rectifier is used in power supplies and electronic devices.

• Examples of rectifiers include Selenium rectifier, Silicon rectifier, and Schottky rectifier.

There are several types of motors used in electrical engineering.

• AC motors: Induction motors, synchronous motors

• DC motors: Brushed DC motors, brushless DC motors

• Stepper motors

• Servo motors

• Linear motors

• Special-purpose motors: Universal motors, reluctance motors, etc.

There are several types of power plants including thermal, hydroelectric, nuclear, solar, wind, and geothermal.

• Thermal power plants use fossil fuels like coal, oil, or natural gas to generate electricity.

• Hydroelectric power plants harness the energy of flowing water to generate electricity.

• Nuclear power plants use nuclear reactions to produce electricity.

• Solar power plants convert sunlight into electricity using photovoltaic cells.

• Wind power plants use wind turbines to genera...read more

Contractor is a device used to make or break an electrical circuit, while relay is an electromagnetic switch that opens or closes circuits.

• Contractor is typically used for high power applications, while relay is used for low power applications.

• Contractor is usually larger in size and can handle higher currents, while relay is smaller and handles lower currents.

• Contractors are commonly used in industrial settings for controlling motors, while relays are used in control circuit...read more

A single line diagram of a basic residential house shows the electrical connections and components in a simplified manner.

• Main service panel receives power from utility company

• Branch circuits for lights, outlets, appliances

• Grounding system for safety

• Optional components like solar panels or backup generator

• Example: Service panel -> Lighting circuit -> Outlet circuit -> Grounding system

Wiring of house power and lights circuit involves proper planning, installation, and maintenance.

• Plan the circuit layout and choose appropriate wires and cables

• Install circuit breakers, switches, and outlets as per safety standards

• Ensure proper grounding and bonding of electrical system

• Regularly inspect and maintain the wiring system to prevent hazards

• Use proper color coding for wires to avoid confusion

• Separate power and lighting circuits to prevent overload

• Install GFCI outle...read more

Miniature Circuit Breaker (MCB) is a device designed to protect electrical circuits from overloads and short circuits.

• MCB stands for Miniature Circuit Breaker

• It is a type of circuit breaker that automatically switches off electrical circuits during abnormal conditions

• MCBs are commonly used in residential, commercial, and industrial applications

• They are available in different ratings such as 6A, 10A, 16A, etc.

• MCBs are more compact and easier to install compared to traditional ...read more

Transformers are electrical devices that transfer electrical energy between two or more circuits through electromagnetic induction.

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

• There are two main types of transformers: step-up transformers and step-down transformers.

• Step-up transformers increase the voltage level, while step-down transformers decrease the voltage level.

• Transformers are essential in power transmission and distribution s...read more

Star delta starter diagram is used for motor starting, transformer safety involves protection measures, and predictive maintenance is proactive while preventive maintenance is scheduled.

• Star delta starter diagram is used for reducing starting current in motors.

• Transformer safety involves measures like overcurrent protection, earth fault protection, and temperature monitoring.

• Predictive maintenance involves using data and analytics to predict when equipment will fail.

• Preventiv...read more

Busbars are used to conduct large currents of electricity in a safe and efficient manner.

• Busbars are made of copper or aluminum and are used to distribute power throughout a building or facility.

• They are often used in switchgear and distribution panels to connect circuit breakers and other electrical equipment.

• Busbars can handle high levels of current without overheating or melting, making them a reliable and safe choice for power distribution.

• They are also used in electrical...read more

Mortar is a mixture of cement, sand, and water used to bind bricks or stones together. There are different types of mortar.

• Mortar is used in construction to bind bricks or stones together

• The most common type of mortar is Portland cement mortar

• Other types of mortar include lime mortar, mud mortar, and epoxy mortar

• The type of mortar used depends on the type of construction and the materials being used

Solar energy is converted into electricity through photovoltaic cells and then distributed through a grid system.

• Solar energy is captured by solar panels, which contain photovoltaic cells that convert sunlight into electricity.

• The electricity generated is then fed into an inverter, which converts it from direct current (DC) to alternating current (AC) for use in homes and businesses.

• The AC electricity is then distributed through a grid system, which delivers power to various ...read more

AC stands for alternating current, which periodically changes direction. DC stands for direct current, which flows in one direction.

• AC is commonly used in household appliances and power distribution systems.

• DC is commonly used in batteries and electronic devices.

• AC changes direction periodically, while DC flows in one direction continuously.

• AC is generated by power stations and transmitted over long distances.

• DC is used in applications where a constant voltage is required, su...read more

A capacitor is an electronic component that stores and releases electrical energy in a circuit.

• Capacitors consist of two conductive plates separated by an insulating material called a dielectric.

• They are used to filter out noise in electronic circuits, store energy in flash cameras, and smooth out voltage fluctuations in power supplies.

• Capacitance is measured in Farads (F) and determines how much charge a capacitor can store for a given voltage.

• Capacitors can be polarized (el...read more

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

• Consists of two or more coils of insulated wire wrapped around a core

• Primary coil receives electrical energy and induces a magnetic field in the core

• Secondary coil receives energy from the magnetic field and transfers it to the load

• Used to step up or step down voltage levels in electrical systems

• Commonly used in power distribution and transmission systems

Nuts and bolts are hardware fasteners used to join two or more objects together.

• Nuts are internally threaded and are used with bolts to fasten objects together.

• Bolts are externally threaded and have a head at one end and a threaded shank at the other end.

• Nuts and bolts come in various sizes and materials, including steel, brass, and aluminum.

• They are commonly used in construction, automotive, and manufacturing industries.

• Examples of nuts and bolts include hex bolts, carriage ...read more

Losses in transformers include copper losses, iron losses, and stray losses.

• Copper losses occur due to resistance in the windings and are proportional to the square of the current flowing through the transformer.

• Iron losses, also known as core losses, include hysteresis losses and eddy current losses in the transformer core material.

• Stray losses are caused by leakage flux and are difficult to quantify accurately.

• Total losses in a transformer are the sum of copper losses and i...read more

Diodes are electronic components that allow current to flow in one direction only. Common types include PN junction diodes, Zener diodes, Schottky diodes, and light-emitting diodes (LEDs).

• PN junction diodes: Basic diodes that allow current to flow in one direction only.

• Zener diodes: Diodes that operate in the reverse breakdown region and are used for voltage regulation.

• Schottky diodes: Diodes with a lower forward voltage drop compared to PN junction diodes.

• Light-emitting diod...read more

A fuse is a one-time use device that melts when there is an overload, while an MCB is a reusable device that trips when there is an overload.

• Fuse is a one-time use device, while MCB is reusable

• Fuse needs to be replaced after it melts, MCB can be reset

• Fuse operates on the principle of thermal or electrical melting, MCB operates on the principle of electromagnetism

• Fuse is slower in response time compared to MCB

• Examples: A glass fuse vs a miniature circuit breaker

A 2 phase transformer is a type of transformer that has two primary and two secondary windings.

• Consists of two primary windings and two secondary windings

• Used in certain industrial applications where a 3 phase transformer is not feasible

• Less common compared to single phase and 3 phase transformers

A 3 phase transformer is a type of transformer that is designed to handle three-phase power distribution systems.

• Consists of three sets of primary and secondary windings

• Used in power distribution systems to step up or step down voltage in three-phase circuits

• Commonly used in industrial and commercial applications

• Examples include distribution transformers, power transformers, and autotransformers

A star delta starter is an electrical motor starting device that reduces the starting current and torque of the motor.

• Used for starting high power motors

• Consists of a contactor and timer

• Initially starts the motor in star configuration and then switches to delta configuration

• Reduces starting current and torque

• Used in industries such as oil and gas, mining, and manufacturing

5S is a workplace organization method that aims to improve efficiency and productivity by maintaining cleanliness and orderliness.

• 5S stands for Sort, Set in Order, Shine, Standardize, and Sustain

• Sort involves removing unnecessary items from the workplace

• Set in Order involves organizing the remaining items in a logical and efficient manner

• Shine involves cleaning and maintaining the workplace

• Standardize involves creating procedures and guidelines for maintaining the workplace

• Su...read more

Feedback is a process that provides information about the output of a system and allows for adjustments to be made.

• Feedback helps in monitoring and controlling the performance of a system.

• It provides information about the output of a system and compares it to the desired or expected output.

• Feedback allows for adjustments to be made to the system to ensure it operates optimally.

• It helps in identifying and correcting errors or deviations from the desired performance.

• Feedback is...read more

Transformers are used to step up or step down voltage levels in electrical circuits.

• Transformers consist of primary and secondary coils wound around a core

• Step-up transformers increase voltage levels, while step-down transformers decrease voltage levels

• Transformers work on the principle of electromagnetic induction

• They are used in power distribution systems, electrical appliances, and electronic devices

Motor starters with contactors provide protection by controlling the electrical supply to the motor.

• Motor starters with contactors prevent overload by disconnecting the motor from the power supply when excessive current is detected.

• They also protect against short circuits by quickly interrupting the circuit in case of a fault.

• Thermal overload relays can be used in conjunction with contactors to provide additional protection by monitoring the motor's temperature.

• Motor starters...read more

There are two main types of motors: AC motors and DC motors.

• AC motors are powered by alternating current and are commonly used in household appliances and industrial machinery.

• DC motors are powered by direct current and are commonly used in electric vehicles and robotics.

• Other types of motors include stepper motors, servo motors, and linear motors.

• Stepper motors are used in precision control applications, while servo motors are used in robotics and automation.

• Linear motors ar...read more

A supervisor in the field of electrical engineering is responsible for overseeing and managing the work of a team or department.

• Supervising and coordinating the activities of electrical engineers and technicians

• Planning and organizing work schedules and assignments

• Ensuring compliance with safety regulations and quality standards

• Providing technical guidance and support to team members

• Monitoring progress and performance of projects

• Resolving any issues or conflicts that arise

• Rev...read more

AC motors use alternating current and are more commonly used for industrial applications, while DC motors use direct current and are often used in household appliances.

• AC motors use alternating current, while DC motors use direct current

• AC motors are more commonly used in industrial applications, while DC motors are often used in household appliances

• AC motors are generally more efficient and require less maintenance compared to DC motors

• AC motors are easier to control speed a...read more

Types of motors include DC motors, AC motors (induction, synchronous), stepper motors, and servo motors. Each type operates based on different principles.

• DC motors operate on the principle of Lorentz force, where a current-carrying conductor experiences a force in a magnetic field.

• AC induction motors work on the principle of electromagnetic induction, where a rotating magnetic field induces current in the rotor.

• AC synchronous motors operate by synchronizing the speed of the r...read more

Types of motors include DC motors, AC motors, synchronous motors, and induction motors. Each type operates based on different principles.

• DC motors operate using direct current and have a commutator to switch the current direction, examples include brushed and brushless DC motors.

• AC motors operate using alternating current and include types like synchronous motors and induction motors.

• Synchronous motors rotate at a constant speed determined by the frequency of the AC power sup...read more

The type of motor can be AC or DC, while the type of transformer can be step-up or step-down.

• AC motors are commonly used in household appliances and industrial machinery.

• DC motors are often used in electric vehicles and robotics.

• Step-up transformers increase voltage while step-down transformers decrease voltage.

• Transformers are used in power distribution systems to transfer electrical energy between different voltage levels.

Capacitors are used to store and release electrical energy in circuits.

• Capacitors are passive electronic components that can store electrical energy in an electric field.

• They are commonly used in power supplies, filters, timing circuits, and audio equipment.

• Capacitors can help smooth out voltage fluctuations and reduce noise in electronic circuits.

• They can also be used in conjunction with resistors to create timing circuits.

• Examples of capacitors include ceramic, electrolytic...read more

A motor is a device that converts electrical energy into mechanical energy based on the principles of electromagnetism.

• A motor consists of a rotor and a stator.

• When an electric current flows through the stator windings, it creates a magnetic field.

• The interaction between the magnetic field and the rotor's magnetic field causes the rotor to rotate.

• Motors can be classified into various types such as DC motors, AC motors, synchronous motors, and induction motors.

• Examples of moto...read more

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

• Transformers are used to increase or decrease the voltage in an electrical circuit.

• They consist of two or more coils of wire, known as windings, that are wound around a core made of magnetic material.

• The primary winding is connected to the power source, while the secondary winding is connected to the load.

• The transformer operates based on the p...read more

GD stands for Group Discussion, a method of assessing communication and interpersonal skills of candidates.

• GD is a common selection process used by companies to evaluate candidates.

• It involves a group of candidates discussing a given topic and presenting their views.

• The purpose is to assess communication skills, leadership qualities, and ability to work in a team.

• GDs can be structured or unstructured, and may have a moderator to guide the discussion.

• Examples of topics for GDs...read more

A conductor is a material that allows the flow of electric current.

• Conductors have low resistance to the flow of electricity.

• Metals like copper and aluminum are commonly used as conductors.

• Conductors are used in electrical wiring, circuits, and transmission lines.

The electrical resistance is a measure of how much an object opposes the flow of electric current.

• Electrical resistance is measured in ohms (Ω).

• It is determined by the material and dimensions of an object.

• Higher resistance means less current flow.

• Example: A light bulb has a high resistance, which causes it to glow when current passes through.

A semiconductor is a material that has electrical conductivity between that of a conductor and an insulator.

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

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

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

Solar power plant maintenance involves regular cleaning of panels, inspection of components, and monitoring of performance.

• Regularly clean solar panels to remove dirt and debris that can reduce efficiency

• Inspect components such as inverters, wiring, and batteries for any signs of wear or damage

• Monitor performance metrics like energy output and system efficiency to identify any issues early

• Schedule regular maintenance checks by trained professionals to ensure optimal performan...read more

A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally iron.

• Used for smelting iron ores to produce iron

• Consists of a furnace chamber with a stack and tuyeres

• Operates at high temperatures using coke as fuel

• Produces molten iron and slag as byproducts