Sähkövirtaa
Sähkövirtaa, often translated as electric current, is the flow of electric charge. This charge is typically carried by electrons in a conductor. The movement of these charged particles creates an electric current. The direction of conventional current is defined as the direction of positive charge flow, even though in most common conductors, it is the negatively charged electrons that move. The strength of an electric current is measured in amperes (A). One ampere is equivalent to one coulomb of charge passing a point in one second. Electric current is a fundamental concept in electricity and is essential for the operation of countless devices and systems, from household appliances to complex electronic circuits. It is the basis of electrical power and its transmission. The flow of charge requires a potential difference, also known as voltage, to drive it through a circuit. Without a voltage source, such as a battery or a generator, electric charges will not move in a sustained manner. The relationship between voltage, current, and resistance in a circuit is described by Ohm's Law. Current can be either direct current (DC), where the charge flows in one direction, or alternating current (AC), where the direction of charge flow periodically reverses.