L&T Construction Electrical Technician Interview Questions and Answers

Types of transformers include power transformers, distribution transformers, instrument transformers. Types of electrical drives include AC drives, DC drives, servo drives.

• Power transformers are used in high voltage transmission and distribution systems.

• Distribution transformers are used to step down voltage for use in homes and businesses.

• Instrument transformers are used for measuring voltage and current in power systems.

• AC drives control the speed of AC motors.

• DC drives con...read more

The process for entering single-phase voltage involves connecting the voltage source to the load through a single conductor.

• Connect the single-phase voltage source to the load through a single conductor

• Ensure proper insulation and grounding for safety

• Check the voltage level using a multimeter before connecting the load

• Make sure the load is compatible with the voltage rating

Current is the flow of electric charge, measured in Amperes, while voltage is the force that drives the current, measured in Volts.

• Current is the rate of flow of electric charge in a circuit

• Voltage is the electrical potential difference that drives the current

• Current is measured in Amperes (A)

• Voltage is measured in Volts (V)

• Ohm's Law states that V = I * R, where V is voltage, I is current, and R is resistance

Three-phase voltage is a type of electrical power transmission that utilizes three alternating currents.

• Three-phase voltage consists of three alternating currents that are 120 degrees out of phase with each other.

• It is commonly used in industrial and commercial applications for its efficiency and power distribution capabilities.

• The voltage levels for three-phase systems can vary depending on the application, with common values being 208V, 240V, 480V, and 600V.

• Three-phase volt...read more

Unit slip is the difference between synchronous speed and rotor speed in an induction motor.

• Unit slip is expressed as a fraction or percentage.

• It is used to calculate the rotor speed of an induction motor.

• Unit slip is necessary for determining the torque and efficiency of the motor.

• For example, if the synchronous speed of a motor is 1800 RPM and the rotor speed is 1750 RPM, the unit slip would be 0.0278 or 2.78%.

A slip ring is an electrical component used to transfer power and electrical signals from a stationary to a rotating structure.

• Allows for continuous rotation without tangling wires

• Commonly used in electromechanical systems like motors, generators, and wind turbines

• Consists of stationary brushes and rotating conductive rings

• Helps in transmitting power, data, and signals across rotating interfaces

Types of motors include AC motors, DC motors, synchronous motors, asynchronous motors, stepper motors, and servo motors.

• AC motors: Alternating current motors commonly used in household appliances and industrial applications.

• DC motors: Direct current motors used in applications where speed control is important.

• Synchronous motors: Maintain a constant speed and are used in applications like clocks and timers.

• Asynchronous motors: Also known as induction motors, they are commonly ...read more