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Electricity is the flow of electric charges through a metal. The flow of electric charges can be expressed in terms of the potential difference, current, voltage and resistance. Charge and current are closely related concepts that are explored in this post. Electricity is a physical phenomenon in which charged particles flow from one place to another. Its nature is best explained by considering its flow through a metal that serves as a conductor.
The Potential difference is the flow of electric charges through a conductor due to the difference in the electrical potentials at the two ends of the conductor.
Electric charge and current:
Electric charge is the sum of the positive and negative charges, which can exist on a single particle or spread throughout multiple particles. The charge on an individual atom of an element is fixed by nature. However, when two atoms combine to form a molecule, the charge may vary.
Electric current is the rate at which electrons flow through a conductor. It is measured in amperes (A), or the number of Coulombs (the standard unit of charge) that pass a given point per second.
The Potential difference:
They must possess a significant potential difference across their lengths to flow electricity through conductors. The potential difference is the energy required to move an electric charge of 1 coulomb (C) from one point to another.
- A standard SI unit for the potential difference is “volt” (V), which is defined as the potential energy required to move a charge of 1 C from one point in time against a force of 1 newton (N) between two points.
- The SI unit for measuring electrical current is “ampere” (A).
A metallic conductor is a material that conducts electric current due to the movement of electrons within its atoms. A metal must have movable electrons responsible for carrying electric currents to conduct electricity. It is also necessary that the metal has free atoms or ionised impurities. The main property of a metal that makes it suitable for conduction is the density of these movable electrons.
The type of metal does not matter as much as its chemical composition, which determines the number of atoms packed into a specific space and the number of electrons in those atoms. Metals with a high density of movable electrons are called conducting metals, while those with a lower density are called insulating metals.
There are many ways to measure electric current using voltage, resistance and charge. This can be done by passing electricity through an unknown object and measuring how much flow changes as the voltage increases or decreases. The current can also be recorded at two different voltages. If the current is measured at one voltage and the voltage is then changed, the flow direction will be determined by how the current changes.
The amount of charge that flows through a physical object due to a change in electric potential has been measured, known as “voltage.” However, the change in electric potential across a physical object is equivalent to the movement of electrons through that object – i.e. “current.” Voltage is the driving force behind a current, but it is not the current itself.
Voltage and current are always related to a conductor. A device that measures an electric current is called an ammeter, while one that measures a voltage difference is called a voltmeter. A device that measures both voltages and currents is called a multimeter.
Resistance:
Resistance is the opposition to electric flow through an object. This can be expressed as Ohms, V/A or Ω(Omega). The result of either free-standing elements or a solid conductor is resistance.
Resistance is not always in constant proportion to voltage, especially in thin films and semiconductors, because the resistance depends on the temperature and the material’s microstructure. In rare cases, resistivity can become infinite at low temperatures. In such cases, the resistance can be infinite but never displays any significant change with changing temperature.
Relation between current, voltage and resistance:
Ohm’s law relates current, voltage and resistance: “V” = “I” × “R.”
Where “V” is the voltage (the electric potential difference), “I” is the current and “R” is the resistance. In the International System of Units or SI, the Ohm (symbol Ω) is the resistance unit. The unit of current is the ampere (symbol A). The unit of voltage is the volt (symbol V).
Resistance is a part of the electrical resistance: “R” = “Z” “, where “Z” is the electrical resistivity. Materials with low resistivity are called semiconductors and exhibit ohmic behaviour.
In the absence of electricity, there is no such thing as a neutral or negative charge. If a conductor has no electrons moving around, it will have zero resistance and zero voltage.
Conclusion:
We have observed that the current and voltage in a conductor are related by Ohm’s law, which can be proven by using the resistivity of a material. Also, we know that current is related to the voltage by Ohm’s law. Therefore, “current is dependent on voltage.” Potential difference or voltage is used to make current flow through a conductor. It can be measured in volts; however, the origin of the potential difference comes from potential energy, the driving force behind electric current. Voltage is a measurement of potential energy, while resistance is a measurement of opposition to electric flow.
