The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
Electric current is an important concept that explains the passing of energy. The article will talk about current electricity and the factors that influence it.
Current per unit time is referred to as the passage of charge through an area. A closed-circuit is vital for a steady flow of electricity. Current electricity talks about the dynamic nature of electricity. The electric charge comes from an external source that moves to a higher potential from a lower potential. Electromotive force refers to the work done by a unit charge to move the charge.
The Ohm’s Law states that the electric current that flows through a substance is directly proportional to the voltage present across ends. This electricity is carried by negatively charged particles, known as electrons. In some cases, these particles are also known as ionic crystals, electrolytic liquid, etc.
Ohm’s Law: Voltage = current x resistance.
Some drawbacks of Ohm’s Law are:
There are specific rules that govern current electricity. Some of the laws are:
Resistance refers to the hindrances present in the electrical circuit that oppose the flow of current. It is measured in Ohms. Ohms is symbolised by the Greek symbol of Omega. With more resistance, the flow of electrons is reduced. If a material offers low resistance, the negatively charged particles can easily move through the substance. The resistance depends on the following 2 factors:
Resistivity is the electrical resistance of a conductor. It talks about the resistance of a unit cross-sectional area and a unit length. The SI unit of resistance is Ohm meters. It is defined in terms of the magnitude of the electric field and the magnitude of current density which is measured in ampere per square metres. Materials like copper, silver, which are generally used as conductors have a low resistivity. However, in the case of insulators, the resistance is relatively high, thus obstructing the flow of electric current. These insulators include water, wood, etc.
Temperature Dependence of Resistivity is an established phenomenon. Given below are some of the factors on which resistivity depends:
Origin of Resistivity
Resistivity comes into picture when current is passed through the substance. Due to this current, the drift of electrons takes place, which influences resistivity; the particles suffer collisions bringing resistivity into the picture. Also, the drift velocity’s direction to the conduction electrons will always be opposite to the electric field direction.
A noteworthy phenomenon, Superconductivity is observed when the electric current moves through a substance without facing any electrical resistance. This is a situation of perfect efficiency as the current gets passed from one point to another without any resistance. This also means that the velocity of electricity is not disrupted and there is no loss of energy that takes place on the way from one point to another point of the circuit.
The device used for measuring the potential difference between two points is known as the potentiometer.
Alternatively, this device can also be effectively used to measure the internal resistance that is present in a circuit. Also, it helps in measuring the difference between two points within the circuit.
Understanding the concept of current electricity is essential to learn how electricity flows from one point to another. Also, another critical aspect of it is it will help you in building circuits. Electric current is a free charge that moves from a body of higher potential to a body having low potential. Learn more concepts on electricity with real life examples on the MSVgo app.