When analyzing electrical circuits, the actual direction of current through a specific circuit element is usually unknown until the analysis is completed. Reference directionĪ current in a wire or circuit element can flow in either of two directions. Negatively charged carriers, such as the electrons (the charge carriers in metal wires and many other electronic circuit components), therefore flow in the opposite direction of conventional current flow in an electrical circuit. Since current can be the flow of either positive or negative charges, or both, a convention is needed for the direction of current that is independent of the type of charge carriers. Positive and negative charge carriers may even be present at the same time, as happens in an electrolyte in an electrochemical cell.Ī flow of positive charges gives the same electric current, and has the same effect in a circuit, as an equal flow of negative charges in the opposite direction. In other materials, notably the semiconductors, the charge carriers can be positive or negative, depending on the dopant used. In metals, which make up the wires and other conductors in most electrical circuits, the positively charged atomic nuclei of the atoms are held in a fixed position, and the negatively charged electrons are the charge carriers, free to move about in the metal. In a conductive material, the moving charged particles that constitute the electric current are called charge carriers. The conventional direction of current, also known as conventional current, is arbitrarily defined as the direction in which positive charges flow. The symbol for a battery in a circuit diagram. Conventions The electrons, the charge carriers in an electrical circuit, flow in the opposite direction of the conventional electric current. The notation travelled from France to Great Britain, where it became standard, although at least one journal did not change from using C to I until 1896. The I symbol was used by André-Marie Ampère, after whom the unit of electric current is named, in formulating Ampère's force law (1820). Current intensity is often referred to simply as current. The conventional symbol for current is I, which originates from the French phrase intensité du courant, (current intensity). Time-varying currents emit electromagnetic waves, which are used in telecommunications to broadcast information. In ordinary conductors, they cause Joule heating, which creates light in incandescent light bulbs. : 788Įlectric currents create magnetic fields, which are used in motors, generators, inductors, and transformers. : 15 Electric current is also known as amperage and is measured using a device called an ammeter. The ampere is an SI base unit and electric current is a base quantity in the International System of Quantities (ISQ). In the International System of Units (SI), electric current is expressed in units of ampere (sometimes called an "amp", symbol A), which is equivalent to one coulomb per second. In an electrolyte the charge carriers are ions, while in plasma, an ionized gas, they are ions and electrons. In semiconductors they can be electrons or holes. In electric circuits the charge carriers are often electrons moving through a wire. : 2 : 622 The moving particles are called charge carriers, which may be one of several types of particles, depending on the conductor. It is defined as the net rate of flow of electric charge through a surface. An electric current is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |