L&T Construction Electrical Engineer Interview Questions and Answers

SMT stands for Surface Mount Technology, a method of electronic component assembly where components are mounted directly onto the surface of a printed circuit board (PCB).

• SMT components are smaller and lighter than through-hole components, allowing for higher component density on PCBs.

• SMT components are typically mounted using solder paste and reflow soldering techniques.

• SMT technology allows for automated assembl...read more

Resistance is the opposition to the flow of current in a circuit, while a capacitor stores and releases electrical energy.

• Resistance limits the flow of current, while a capacitor stores and releases charge.

• Resistance is measured in ohms, while capacitance is measured in farads.

• Examples of resistors include carbon film resistors, while examples of capacitors include ceramic capacitors.

• Resistance dissipates energy i...read more

PCB stands for Printed Circuit Board, a board made of non-conductive material with conductive tracks for electronic components.

• PCB is used to mechanically support and electrically connect electronic components using conductive pathways.

• It is made of non-conductive material like fiberglass, with copper tracks to connect components.

• PCBs can be single-sided, double-sided, or multi-layered depending on the complexity ...read more

Active components require a power source to operate, while passive components do not.

• Active components require an external power source to function, such as transistors and integrated circuits.

• Passive components do not require an external power source, such as resistors and capacitors.

• Active components can control the flow of electricity, while passive components simply store or dissipate energy.

• Examples of active...read more

Speed control methods of induction motor include voltage control, frequency control, and rotor resistance control.

• Voltage control: By varying the voltage supplied to the motor, the speed can be controlled.

• Frequency control: By changing the frequency of the power supply to the motor, the speed can be adjusted.

• Rotor resistance control: By inserting external resistance in the rotor circuit, the speed can be regulated...read more

Current is the flow of electric charge through a conductor.

• Current is measured in amperes (A).

• It is caused by the movement of electrons or ions.

• Current can be either direct current (DC) or alternating current (AC).

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

• Examples of current include the flow of electricity in a circuit or the movement of ions in an electrolyte solution.

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 of an alternating current (AC) signal.

• 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 receives electrical energy from a power source, wh...read more