11 Basic Electrical Engineering Interview Questions and Answers

Electrical Engineering involves the designing of electrical machines and systems. On the other hand, hiring managers are concerned that they hire electrical engineers with the proper training and skills to help you grow while meeting their clients’ demands. It is good to be ready for these electrical engineering interview questions to become an electrical engineer.

What is the meaning of Electrical Engineering?    

It is a field that deals with studying and application of electronics, electricity, and electromagnetism. Also, they deal with high voltage for Alternating Current between 110 and 220V. For instance, electrical devices and components use alternate current/voltages, and they are more extensive. In the United Kingdom, they use 230V, while the United States uses 110V single-phase AC voltages, but the reverse is the case for power stations and industries.

Electrical Engineering Interview Questions

  1. What do Capacitance and Inductance mean?

Capacitance is the charge present inside a capacitor at any given voltage. At the same time, Inductance is the property of a coil that helps it resist any changes in electrical current from flowing. Mutual Inductance occurs when a secondary coil opposes the current change inside a primary coil.

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  1. The Difference between Alternator and Generator?

The two-term “alternator and generator” function uses a similar principle to convert mechanical energy into electrical energy.

Alternator: It has a stationary armature and rotating magnetic for offering fixed magnetic field and high voltage and a rotating armature for low voltage.

Generator: It helps to convert Electro-Motive Force into direct current. It is based on a stationary magnetic field with a revolving conductor rolling on the armature alongside the slip rings and brushes riding on each other.

  1. What are the kinds of cables for transmission?

We have three different kinds of cables based on their thermal capacities, which are:

Low tension cables for transmitting voltage from 1000 volts

High tension cables for transmitting voltage from 23000 volts

Super tension cables for transmitting voltage 66kv to 132kv

  1. What are the kinds of wire colors and their indication?

It is crucial to have the correct answers for this question:

Red Wire: A secondary live wire inside a 220 voltage circuit used for connections. You have an option to join the red wire to another black wire or red wire.

Green: It connects the grounding terminal in an outlet box to the ground bus bar inside an electric panel.

Black wire: It is for power supply in different circuits, and any circuit with the color is considered hot or live. You can’t use it for a ground or neutral wire.

White and Gray: It is a neutral wire and carries the current to the ground. The two colors are joined together.

Blue and Yellow wire: They carry power, but they aren’t wiring the outlets for standard plug-in electrical devices, and live wire is pulled via the conductor. You can see the yellow wire in switched outlets, fans, and structure lights.

  1. Explain the RLC circuit?

The circuit carries an electrical circuit that comprises an inductor, resistor, and capacitor connected in series or parallel. You can call the circuit a second-order circuit because any current or voltage can function as a second-order differential equation.

  1. Can you explain how one can decide the electrical wire size they need?

The American Wire Guage System is used for sizing wires. Therefore, the installation of conductors depends on the wire capacity and gauge of the wire. For cables, the smaller the wire Guage, the larger the ampacity of the wire that will be handling the current. For instance, low vol lighting and lamp cords have 18 gauge, while large electric heaters or electric furnaces have six gauges.

  1. How do PNP and NPN transistors function?

In a circuit when an NPN is used,

There will be no current flowing from A to D = No electric flow from X to Z

When a PNP is used,

No electrical current flowing from A to D = Electrical current flows from X to Z

Therefore, the current flowing from A to D is equivalent to no current flow from X to Z

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  1. What is reverse polarity, and how can you fix it?

It is a state where one or more receptacles are joined incorrectly. To repair reverse polarity, you will check the wire connection at the outlet to inspect the receptacle. In a receptacle with reverse polarity, the wire will be a screw to the black wire and the hot side connected to the neutral side. On the other hand, you can swap the cables to resolve the issue.

  1. What is a Laser Diode?

They are compact transistors with either two or more electrical leads. Lasing can occur when a stimulated emission results in photon amplification coming to the lase more. The photons can hit back and forth between the front and back mirror, causing a diverging beam emission from the laser diode packages.

  1. What is active, apparent, complex, and reactive power?

Active Power is the real power delivered to the load like generators, induction motors, and transformers dissipating into the circuit. It is denoted by P, while its SI unit is Watts W.

Apparent Power: It is regarded as the product of current and voltage without referencing the phase difference between them. It is denoted by Q, and its SI unit is VAR.

Complex Power: The product of current and voltage references the phase difference between them. Also, it is the vector sum of the reactive power and active power denoted by S, measured in VAR.

Reactive Power: The power goes back and forth between the source and load. Q denotes it, while the SI unit is VAR (Voltage Ampere Reactive).

  1. What is the difference between primary and secondary cells?

The primary cell happens to be a non-rechargeable battery that users can recharge by any given method. When they are fully discharged, they are disposed of. The primary cell is standard in remote controllers, toys, and handheld devices.

Secondary cells are rechargeable batteries for users to recharge after several usages, depending on their life cycle. They are more expensive compared to primary cells. You can find them in mobile phones, generators, vehicles, etc.

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Electrical engineering interview questions are technical questions that require you to give accurate and simple responses during the interview. Studying some areas or checking online to see some common electrical engineering interview questions the interviewer might ask you to increase your chances of getting the job.

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