JSW Steel Electrical Operations and Maintenance Engineer Interview Questions and Answers

A relay is an electrical device that acts as a switch to control the flow of current in an electrical circuit.

• Relays are used to control high-power devices with low-power signals.

• They consist of an electromagnet and a set of contacts.

• When the electromagnet is energized, it creates a magnetic field that attracts or releases the contacts, allowing or interrupting the flow of current.

• Relays are commonly used in industrial...read more

Reverse forward draw is a control wiring method used in electrical systems to control the direction of rotation of a motor.

• Reverse forward draw is used to control the direction of rotation of a motor.

• It involves the use of a forward contactor and a reverse contactor.

• The control wiring includes connections between the contactors, motor, and power supply.

• By energizing the forward contactor, the motor rotates in one direc...read more

An AC motor is a type of electric motor that operates on alternating current.

• AC motor stands for Alternating Current motor.

• It converts electrical energy into mechanical energy.

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

• They are more efficient and require less maintenance compared to DC motors.

• Examples of AC motors include induction motors, synchronous motors, and brushless m

AC motors and DC motors differ in their power source, construction, speed control, and applications.

• AC motors run on alternating current, while DC motors run on direct current.

• AC motors are more commonly used in household appliances, industrial machinery, and electric vehicles.

• DC motors are often found in battery-powered devices, such as laptops, electric cars, and robots.

• AC motors have a simpler construction with fewe...read more

MCB stands for Miniature Circuit Breaker.

• MCB is an electrical switch that automatically interrupts the flow of current in an electrical circuit during an overload or short circuit.

• It is a type of circuit breaker that is commonly used in residential and commercial buildings.

• MCBs are designed to protect electrical circuits and appliances from damage caused by excessive current.

• They are compact in size and can be easily i...read more

A timer is a device that measures and controls the passage of time.

• A timer is used to initiate or stop a process at a specific time or after a specific duration.

• Timers can be mechanical or electronic.

• They are commonly used in various applications such as appliances, industrial machinery, and automation systems.

• Examples of timers include kitchen timers, programmable thermostats, and countdown timers in sports events.

VFD stands for Variable Frequency Drive.

• VFD is an electronic device used to control the speed and torque of an electric motor.

• It adjusts the frequency and voltage supplied to the motor, allowing for precise control of motor speed.

• VFDs are commonly used in industrial applications to save energy, improve motor performance, and enable soft starting and stopping.

• They are also known as AC drives, adjustable speed drives, or...read more

PLC stands for Programmable Logic Controller. It is a digital computer used for automation of electromechanical processes.

• PLC is a specialized computer designed to control industrial processes.

• It uses a programmable memory to store instructions and execute them in a sequential manner.

• PLCs are commonly used in manufacturing plants, power stations, and other industrial settings.

• They can be programmed to control various d...read more

An AC motor is a type of electric motor that operates on alternating current.

• AC motor stands for alternating current motor.

• It converts electrical energy into mechanical energy.

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

• They are more efficient and require less maintenance compared to DC motors.

• Examples of AC motors include induction motors, synchronous motors, and brushless m

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 are made up of diodes, which allow current to flow in only one direction.

• Rectifiers can be half-wave or full-wave, depending on the number of diodes used.

• Examples of rectifiers include bridge rectifiers, vacuum tube rectifiers, and soli

A diode is an electronic component that allows current to flow in one direction and blocks it in the opposite direction.

• Diodes are commonly used in rectifier circuits to convert AC to DC.

• They have two terminals: an anode (positive) and a cathode (negative).

• When the voltage across a diode is forward-biased, it allows current to flow.

• When the voltage is reverse-biased, it blocks the current.

• Diodes are often used for volt...read more

PLC stands for Programmable Logic Controller. It is a digital computer used for automation of electromechanical processes.

• PLC is used to control and monitor industrial processes.

• It is programmed using ladder logic or other programming languages.

• PLCs are commonly used in manufacturing, power plants, and transportation systems.

• They can be used to control motors, valves, sensors, and other devices.

• PLCs provide real-time m...read more

A timer is a device or software that measures and controls the passage of time.

• A timer can be a physical device with buttons and a display, or it can be a software program on a computer or smartphone.

• Timers are commonly used in various applications such as cooking, sports, and industrial processes.

• They can be set to count down from a specific time or count up from zero.

• Some timers have additional features like alarms, ...read more