Sähkövirtausta

Sähkövirtausta, commonly translated as electric current, is the flow of electric charge. This charge is typically carried by electrons, which are subatomic particles with a negative electrical charge. In conductors, such as metals, electrons are loosely bound to their atoms and can move relatively freely. When a voltage difference, or electrical potential difference, is applied across a conductor, these free electrons are driven to move in a particular direction, creating an electric current.

The SI unit for electric current is the ampere (A), named after the French physicist André-Marie Ampère. One ampere is defined as one coulomb of charge passing a point in one second. The direction of conventional current is defined as the direction of positive charge flow, even though in most metallic conductors, it is the negatively charged electrons that are actually moving in the opposite direction.

Electric current is a fundamental concept in electricity and electronics. It is responsible for powering everything from light bulbs and household appliances to complex electronic devices. The behavior of electric currents is described by Ohm's Law, which relates voltage, current, and resistance. Resistance is a property of a material that opposes the flow of electric current. Materials with low resistance, like copper, are good conductors, while materials with high resistance, like rubber, are insulators. Understanding sähkövirtausta is crucial for designing and analyzing electrical circuits.