Electrical Circuitry

Electrical circuit refers to the path for transmitting electrical current. How electrical circuits work is that they consist of a source of electrical power, wires that carry electrical current and the destination which is an electrical component such as a bulb or other electrical devices. A circuit constitutes an interconnection of elements on the basis of their ability to generate energy that are classified into passive and active elements. The passive elements include capacitors, resistors, and inductors. There are two basic laws that mathematically describe the performance of electric circuits that is kirchoff’s rules and ohnm’s law. 

An ideal source voltage is considered to be independent of the circuit current. In instances when current flows out of the positive terminal voltage source supplies immense power to the circuit. On the other hand, when current flows into the positive terminal power is consumed. Ideally there is no power limit on the amount of power a perfect voltage source has the capacity to absorb. 

PASSIVE ELEMENTS  

1.Resistance:

Resistance refers to the property of a substance that opposes the flow of charge or electricity through it. Conductors offer little resistance thus readily allow electricity to flow through them. Insulating material often have a high resistance that inhibits flow of electricity through the material. Resistance is measured in in ohms (Ω).

Ohm’s law states that the voltage across a resistor equals the product of the current flowing through it and the resistance of the resistor. It may be expressed mathematically as : V = IR

Resistance of material particularly a conducting material varies according to:

a. Length: it’s directly proportional to length

b. Cross sectional Area: it’s inversely proportional to the conductor’s cross-sectional area

c. Nature: Dependent on the nature of the material 

d. Temperature: Resistance impacts the conductor’s temperature

Resistance of the conductor is given by the formula R = ρl/A 

A- cross-sectional area, ρ-resistivity of the material, and l- length of the conductor

2. Inductance:

Inductance refers to the storage element that has the capacity to store and deliver energy; however, its energy-handing capacity is limited. Also, an inductor stores energy in the form of a magnetic field. Inductance is measured in Henry (H). 

Inductance of an inductor is dependent on the following factors:

a. Permeability: It’s directly proportional to the permeability of the magnetic material over which the coil is wound.

b. Cross-sectional area: it’s directly proportional to coil’s cross-sectional area.

c. Coil’s length: It’s inversely proportional to the coil’s length. 

d. Square of the number of coils: it’s directly proportional to the square of the numbers of coils

3. Capacitance

A capacitor is a passive element that stores energy in the form of an electric field. Farad (F) is the unit of capacitance. A capacitor mainly consists of two conducting plates separated by a  dielectric material. A capacitor holds a positive charge when a positive voltage is placed across it. On the other hand, a capacitor stores negative charge when negative voltage is placed across it. A capacitor allows alternating current to pass through them but stops direct current. Therefore, capacitors are often used as filters for non-A.C components of current.

The quantity of charge stored in the capacitor is proportional to the applied voltage across it having a linear relationship can be expressed as follows. 

Q ∝ V  Charge is directly proportional to voltage 

⇒ Q = CV

C- Conductor’s capacitance  

Q- Charge held in a capacitor 

Capacitance of a capacitor are determined by the following factors:

1. Surface area of the plate:  Directly proportional to the surface area of the plate
2. Distance between the two plates: Inversely proportional to the distance between the two plates.

Permittivity of the dielectric (medium between the two charged plates): Proportional to the permittivity of the dielectric

Why is electrical wiring usually made from copper?

One unique thing about electrical circuitry regards copper. Copper is vital in electrical wiring as it is a good conductor of electricity. Free electrons in metals have the ability to move through metals enabling metals to conduct electricity. 

There are numerous reasons why copper is critical in regards to electrical wiring. 

Some of the reasons include: 

• High conductivity: Copper has immensely high conductivity as it is only surpassed by silver. In regards to conductivity electricity can pass through it with great ease thus, making it vital to use in the creation of electric wires. Also, by using copper electrical current can travel for longer distances.

• Inexpensive: Copper is used in the electrical circuits as it is relatively inexpensive compared to other metals that are excellent conductors of electricity such as silver or gold. For instance, manufacturing electric wires using gold can be a significant waste of money. Therefore, the inexpensive nature of copper makes it a de-facto standard for electric wires.

• High ductility: Copper is  metal that is ductile where it has the capability to flex and bend to some extent without breaking or sustaining damage. The ductile nature of the metals are essential as electric wires often travel through ceiling, floors, walls and other tight spaces while still maintaining the capacity to transmit electricity without losing power strength from the shape deformity. 

• Thermal resistance: Thermal resistance is a property that is often overlooked as a crucial benefit, however, to take into account the electrical fires. Electrical fires are responsible for damaging numerous residential and commercial buildings on an annual basis. Using copper for electrical circuitry can play a crucial role in safeguarding buildings from electrical fires. 

There are numerous ways to classify electrical circuits including direct-current circuits that mainly allow flow of electricity in one direction. Alternating current circuit that carries current that pulsates back and forth numerous times each second this is mainly found in most households. For a series circuit this includes a path where the entire current flows through each component of the circuit. For a parallel circuit  the current divides only part of the circuit and only a part of the current flows through that particular branch. 

In a parallel circuit the potential difference or voltage across each branch of a parallel circuit is the same but the currents are varied. For instance, in a home electrical circuit the same voltage is applied across each appliance but each appliance draws different amounts of current according to its requirements. A number of similar batteries connected in parallel provides greater current than a single battery, but the voltage is the same for a single battery.