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By JEROME MICHAEL EBRUPHIYO/Job Vacancies/Tuesday, July 20, 2021

List of Electrical and Electronic Engineering Interview Questions and Answers 2021

                              
                            
Good day viewers! Our focus today shall be on how to succeed in an interview exercise for those who are in search of a job in Electrical and Electronic Engineering field. This article will provide the list of electrical and electronic engineering interview questions and answers 2021 as well as frequently asked interview questions by your interviewer.

1. What happens when two positively charged material is placed together?

Two positively charged material place together will yield a repelling action. This is because like poles repel and unlike poles attract.

2. What is referred to the electron in the outer orbit?

Electron in the outer orbit is known as valence.

3. Define the term Capacitance and Inductance?

The amount of charge that is stored inside a capacitor at a given voltage is known as capacitance. Inductance on the other hand is defined as the property of a coil to resist any changes in electric current flowing through it. Mutual inductance happens when a secondary coil opposes current change in the primary coil.

4. What is the difference between generator and alternator?

Generator converts induced emf (Electro Motive Force) into direct current, where it based on stationary magnetic field and revolving conductor which rolls on the armatures with slip rings and brushes riding against each other. While an Alternator has rotating magnetic and stationary armature for high voltage and stationary magnetic field and a rotating armature for low voltage.Both generator and alternator work on the same principle they convert mechanical energy into electrical energy.

5. What are the different kind of cables used for transmissions?

Cables are categorized into three forms according to its thermal capacity Low tension cables- transmits voltage upto 1000 volts, High tension cables- transmits voltage up to 23000 volts and Super tension cables- transmits voltage up to 66kv to 132kv

6. What are the different colors on wires indicates?

  • Black wire: is used for power supply in all circuits. Any circuits with this color is considered hot or live. It is never used for a neutral or ground wire
  • Red wire: is a secondary live wire in a 220 volt circuit and used in some types of interconnection. You can join the red wire to another red wire or to a black wire
  • Blue and Yellow wire: are also used to carry power but are not wiring the outlets for common plug-in electrical devices. They are used for the live wire pulled through the conductor. You will see yellow wire in the fan, structure lights, and switched outlets
  • White and Gray: is used as a neutral wire. It carries the current (unbalanced load) to the ground. You can join white and gray only to other white and gray wires
  • Green: It is connected to the grounding terminal in an outlet box and run from the outlet box to the ground bus bar within an electric panel
  • 7. What is an RLC circuit?

    An RLC circuit carries an electrical circuit consisting of a resistor (R) and inductor (L) and a capacitor (C), connected in parallel or series. This circuit is called a second order circuit as any voltage or current in the circuit can be described by a second order differential equation.

    8. Explain how you can decide what size of electrical wire you need?

    Wire is sized by American Wire Gauge system. Your installation of conductors will depend on a few factors like gauge of the wire, wire capacity, etc. For wires, smaller the wire gauge larger the ampacity or capacity of the wire to handle current. For example, low voltage lighting and lamp cords will have 18 gauge, electric furnaces or large electric heaters are of 6 gauge.

    9. What are the types of semi-conductors?

    The two types of semi-conductors are intrinsic and extrinsic. Extrinsic semi-conductors have N-type semiconductors and P-type semiconductors.

    10. What are transistors comprised of?

    They are comprised of several combination of n-type and p-type semi-conductors.

    11. What is the role of transistor in a Circuit?

    Transistor has the ability of amplifying the current, due to the reason that output power can be higher than the input power.

    12. How does NPN and PNP transistor work?

    In a circuit when NPN is used;
  • No current flowing from A to D = No flow from X to Z
  • Current flowing from A to D = Current allowed to flow from X to Z
  • When PNP is used;
  • No current flowing from A to D = Current is allowed to flow from X to Z
  • Current flowing from A to D = No current flow from X to Z
  • 13. What will be the current if the resistance total in a series circuit doubles?

    If the resistance total in a series circuit doubles the current will reduce to half.

    14. What happens if the series current double?

    If the series current gets double then, the resistance is halved.

    15. What is the function of a string of resistors in a series connection?

    The function of a string of resistors in a series connection is to the source voltage into proportion to their values.

    16. What is meant by reverse polarity and how can it be fixed?

    Reverse polarity is referred in a condition where one or more of your receptacles are connected incorrectly. To fix the reverse polarity, check the wire connection at the outlet and inspect your receptacle. A receptacle with reverse polarity will have the white wire screwed to the hot side and the black wire will be connected to the neutral side, if that the case swap the wires and it will resolves the problem. If it persists, a licensed electrician will be needed.

    17. What are rectifiers and what are the types of rectifiers?

    A rectifier is an electrical device that transforms A.C or alternating current into direct current (D.C), which flows in only one direction. The types of rectifiers are;
  • Half wave rectifier: It uses one p-n junction and
  • Full wave rectifier: It uses two p-n junction
  • 18. What is Zener diode?

    Zener diode is a type of semi-conductor diode that allows current to flow in the opposite direction when exposed to enough voltage.

    19. Mention the difference between Analogue and Digital circuit?

    Digital circuits operate on continuous valued signals while Analogue circuits operate on the signal which exist at two level 0’s and 1’s. In Digital circuits, no conversion of the input signal required before transmitting, the circuit directly executes various logical operations and produces an analogue output but in Analogue circuits, before the signal is transmitted, it is converted into digital form. There is no probability of losing any information as there is no conversion in Digital circuits. whereas during signal conversion in Analogue circuit, amount of information is lost. Digital circuits anticipate high flexibility while Analogue lacks flexibility.

    20. What is laser diodes?

    Laser diodes are compact transistor like packages with two or more electrical leads. Lasing occurs when stimulated emission results into the amplification of photon confined to the lasing mode. These photons hit back and forth between the back and front mirror, and hence a diverging beam emits from the laser diode packages.
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