SESSION:24

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

When two positively charged material place together it will repel.

2)       Define the term Capacitance and Inductance?

Capacitance: It is the amount of charge that is stored inside a capacitor at a given voltage.

Inductance: It 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.

3)       Mention what is the different kind of cables used for transmissions?

Cables are categorized into three forms according to its thermal capacity

·          Low tension cables- transmits voltage up to 1000 volts

·          High tension cables- transmits voltage up to 23000 volts

·          Super tension cables- transmits voltage up to 66kv to 132kv

4)       Mention what are the different colours on wires indicates?

Black wire: This wire is used for power supply in all circuits. Any circuits with this colour are considered hot or live. It is never used for a neutral or ground wire.

Red wire: This colour 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: These wires 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 conduct. You will see yellow wire in the fan, structure lights, and switched outlets.

White and Gray: This colour wire 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.

5)       Explain 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.

6)       Explain how you decide what size of electrical wire do 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 gauges, electric furnaces or large electric heaters are of 6 gauge.

7)       What is meant by reverse polarity and how it can 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.

8)       Explain what rectifiers are 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

·          Full wave rectifier: It uses two p-n junction

9)       Explain 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.

10)    Explain what are 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.

11)    Mention the difference between Analogue and Digital circuit?

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

12)    How many Types of Circuit Loads are there in a Common Electrical Circuit?

A load generally refers to a component or a piece of equipment connected to the output of an electric circuit. In its fundamental form, the load is represented by any one or a combination of the following:

·         Resistor (R)

·         Inductor (L)

·         Capacitor (C)

A load can either be of resistive, inductive or capacitive nature or a blend of them. For example, a light bulb is a purely resistive load where as a transformer is both inductive and resistive. A circuit load can also be referred to as a sink since it dissipates energy whereas the voltage or current supply can be termed as a source.

13)    Why Inductors are installed in electrical Circuits?

An inductor is a piece of conducting wire generally wrapped around a core of a ferromagnetic material. Like capacitors, they are employed as filters as well but the most well known application is their use in AC transformers or power supplies that converts AC voltage levels.

14)    Briefly explain the purpose of Inductor in an electric circuit?

An inductor is a piece of conducting wire generally wrapped around a core of a ferromagnetic material. Like capacitors, they are employed as filters as well but the most well known application is their use in AC transformers or power supplies that converts AC voltage levels.

15)    What do you mean by dependent and independent voltage sources?

In general, there are two main types of DC sources

·         Independent (Voltage and Current) Sources

·         Dependent (Voltage and Current) Sources

An independent source produces its own voltage and current through some chemical reaction and does not depend on any other voltage or current variable in the circuit. 

The output of a dependent source, on the other hand, is subject to a certain parameter (voltage or current) change in a circuit element. Herein, the discussion shall be confined to independent sources only.