JSW Steel ITI Electrician Interview Questions and Answers

Star delta is a method used to reduce the starting current of electric motors by switching from star to delta configuration.

• Used primarily for three-phase induction motors.

• In star configuration, the voltage across each motor winding is reduced, lowering the starting current.

• After the motor reaches a certain speed, it switches to delta configuration for full power.

• Example: A 50 HP motor may start in star mode to limit t...read more

SMPS (Switched-Mode Power Supply) efficiently converts electrical power using switching regulators.

• SMPS is used in computers to convert AC to DC power.

• It operates by switching on and off rapidly to regulate voltage.

• Examples include power supplies for laptops and LED TVs.

• SMPS is more efficient than traditional linear power supplies.

• It can handle a wide range of input voltages.

DOL stands for Direct On-Line starter, a method used to start electric motors directly from the power supply.

• DOL starters are commonly used for small to medium-sized motors.

• They provide full voltage to the motor, resulting in high starting torque.

• Example: A DOL starter is often used for pumps and fans.

• DOL starters are simple and cost-effective, making them popular in industrial applications.

• They require a contactor and...read more

MCB working principle is to automatically switch off the electrical circuit during abnormal conditions like overload or short circuit.

• MCB detects abnormal conditions like overload or short circuit

• When abnormal condition is detected, MCB trips and disconnects the circuit

• MCB can be manually reset after tripping

• MCB provides protection to electrical circuits and appliances

MCCB stands for Molded Case Circuit Breaker.

• MCCB is a type of circuit breaker that is enclosed in a molded case.

• It is designed to protect electrical circuits from overloads and short circuits.

• MCCBs are commonly used in industrial and commercial applications.

• Examples of MCCB brands include Siemens, Schneider Electric, and ABB.

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

• Consists of two coils of wire, known as primary and secondary windings

• Works on the principle of electromagnetic induction

• Used to step up or step down voltage levels

• Commonly used in power distribution systems

• Examples include power transformers, distribution transformers, and instrument transformers

A motor is a device that converts electrical energy into mechanical energy to perform work.

• Motors are commonly used in various applications such as industrial machinery, household appliances, and vehicles.

• There are different types of motors including AC motors, DC motors, and servo motors.

• Motors consist of a rotor, stator, and various components such as windings, bearings, and brushes.

• The rotation of the motor is gener...read more

VCB stands for Vacuum Circuit Breaker, which is a type of circuit breaker that uses vacuum as the arc quenching medium.

• VCB is used to interrupt the current flow in a circuit by creating a gap between contacts where the arc is extinguished in a vacuum.

• It is commonly used in medium voltage power systems for its high reliability and fast interruption speed.

• VCBs require less maintenance compared to other types of circuit b...read more