Conduction current
Conduction current refers to the flow of electrons through a conductor. When there is a voltage difference across a conductor, electrons flow from a region of high potential to a region of low potential, forming a current.
Electron Flow: In a metallic conductor, electrons are negatively charged particles and they are pushed by force to move in the presence of an electric field. When there is a voltage difference between the two ends of the conductor, the electrons flow along the path of the conductor, moving from a high potential (positive) to a low potential (negative).
Free electrons: The electrons in a metallic conductor are free electrons; they are not tightly bound to atoms and are free to move within the conductor. The presence of free electrons gives metals good electrical conductivity.
Current Density: Current density is the amount of electricity flowing through a conductor per unit area. Its size is related to the strength of the current and the cross-sectional area of the conductor. Current density can be expressed by the formula J = I / A, where J represents the current density, I represents the current intensity, A represents the cross-sectional area of the conductor.
Ohm’s Law : Ohm’s law describes the relationship between current, voltage and resistance. According to Ohm’s law, when the temperature of a conductor is kept constant, the current is directly proportional to the voltage and inversely proportional to the resistance. Ohm’s law can be expressed by the equation V = IR, where V denotes voltage, I denotes current strength, and R denotes resistance.
Thermal effect: When a current is conducted, the movement of electrons in a conductor produces a certain resistance, which leads to a transformation of energy. This transformation produces heat, called Joule heat. When current passes through a conductor, the conductor heats up due to collisions between the electrons and the atoms of the conductor.
Choice of conductor: The choice of conductor is very important when conducting an electric current. The lower the resistance of the conductor, the lower the energy loss when conducting current. Therefore, for high current applications, materials with low resistance are often chosen as conductors to minimize energy loss and heat generation.
Conduction current is a form of electric current that plays an important role in power systems, electronic devices and various circuits. Understanding the properties of conduction current and related concepts helps us to understand the process of current flow, the behavior of electrons, and energy conversion and loss in circuits.
