Voltage, also known as electromotive force, is a quantitative expression of the potential difference in charge between two points in an electrical field. The more the voltage, the greater the flow of electrical current (i.e, the quantity of charge carriers that pass a fixed point per unit of time) through a conducting or semiconducting medium for a given resistance to the flow. Voltage is symbolized by an uppercase italic letter V or E. The standard unit is the volt, symbolized by a non-italic uppercase letter V. One volt will drive one coulomb (6.24 x 1018) charge carriers, such as electrons, through a resistance of one ohm in one second.
Voltage is the difference in electric potential energy per unit charge between two points. Voltage is the work to be done, upon an unit charge to move between two points, against a static electric field. A voltage which is a measure of electric potential difference, is the cause of electrical current to flow in a closed circuit.
Types of voltage:
Voltage is of two types. Direct or Alternating. A direct voltage maintains the same polarity at all times. In an alternating voltage, the polarity reverses direction periodically. The number of complete cycles per second is the frequency, which is measured in hertz (one cycle per second), kilohertz, megahertz, gigahertz, or terahertz. An example of direct voltage is the potential difference between the terminals of an electrochemical cell. Alternating voltage exists between the terminals of a common utility outlet.
A voltage produces an electrostatic field, even if no charge carriers move (that is, no current flows). As the voltage increases between two points separated by a specific distance, the electrostatic field becomes more intense. As the separation increases between two points having a given voltage with respect to each other, the electrostatic flux density diminishes in the region between them.
An inductor, also called a coil or reactor, is a passive two-terminal electrical component which resists changes in electric current passing through it. It consists of a conductor such as a wire, usually wound into a coil. Energy is stored in a magnetic field in the coil as long as current flows.
A capacitor is a passivetwo-terminalelectrical component that stores electrical energy in an electric field. The effect of a capacitor is known as capacitance. While capacitance exists between any two electrical conductors of a circuit in sufficiently close proximity, a capacitor is specifically designed to provide and enhance this effect for a variety of practical applications by consideration of size, shape, and positioning of closely spaced conductors, and the intervening dielectric material. A capacitor was therefore historically first known as an electric condenser in this video you will know basics of capacitors in circuit and electronics
Facts about capacitors
A capacitor is a circuit component made of two conducting surfaces (plates) separated by a dielectric (non-conducting insulator) material.
Capacitor shapes are either flat or rolled (cylinder).
The Leyden jar was the first capacitor created, invented in 1745 by Pieter van Musschenbroek.
A capacitor’s conducting surfaces are made of different materials, including a thin film of conductive metal or aluminum.
The negatively charged plate is known as the cathode and the positively charged plate is known as the anode.
Capacitors with higher capacitance values are made from materials with a higher dielectric constant.
Dielectric materials used in capacitors include ceramic, air, vacuum, paper impregnated with oil or wax, mylar, polystyrene, mica, and glass.
When a capacitor is connected to a power source, positive charges transfer to one of the conducting surfaces, and negative charges are transferred to the other conducting surface.
A capacitor can absorb energy from a circuit and store it temporarily. The capacitor can then later return the energy to the circuit.
Capacitors discharge very slowly, but many can store a charge for years.
Handling a charged capacitor in the wrong way can result in burns or even death, especially if the capacitor is large.
A capacitor is discharged slowly when a resistor is connected to each leg. The resistor must be rated for the same or higher voltage than the capacitor can store for this method of discharge in order to work safely.
Capacitors are measured in a unit called farads, named after the scientist Michael Faraday. This measure is also known as capacitance.
Supercapacitors made with graphene as the conducting plate are capable of storing a charge similar to lithium-ion batteries.