In electrical engineering

Electrical engineering

Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...

, electrical terms are associated into pairs called duals. A dual of a relationship is formed by interchanging voltage and current in an expression. The dual expression thus produced is of the same form, and the reason that the dual is always a valid statement can be traced to the duality of electricity and magnetism.

Here is a partial list of electrical dualities:

• voltage
  Voltage
  Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
  
   — current
  Electric current
  Electric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...
  
  
• parallel — serial
  Series and parallel circuits
  Components of an electrical circuit or electronic circuit can be connected in many different ways. The two simplest of these are called series and parallel and occur very frequently. Components connected in series are connected along a single path, so the same current flows through all of the...
  
   (circuits)
• resistance
  Electrical resistance
  The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical...
  
   — conductance
• impedance
  Electrical impedance
  Electrical impedance, or simply impedance, is the measure of the opposition that an electrical circuit presents to the passage of a current when a voltage is applied. In quantitative terms, it is the complex ratio of the voltage to the current in an alternating current circuit...
  
   — admittance
  Admittance
  In electrical engineering, the admittance is a measure of how easily a circuit or device will allow a current to flow. It is defined as the inverse of the impedance . The SI unit of admittance is the siemens...
  
  
• capacitance
  Capacitance
  In electromagnetism and electronics, capacitance is the ability of a capacitor to store energy in an electric field. Capacitance is also a measure of the amount of electric potential energy stored for a given electric potential. A common form of energy storage device is a parallel-plate capacitor...
  
   — inductance
  Inductance
  In electromagnetism and electronics, inductance is the ability of an inductor to store energy in a magnetic field. Inductors generate an opposing voltage proportional to the rate of change in current in a circuit...
  
  
• reactance — susceptance
  Susceptance
  In electrical engineering, susceptance is the imaginary part of admittance. The inverse of admittance is impedance and the real part of admittance is conductance. In SI units, susceptance is measured in siemens...
  
  
• short circuit
  Short circuit
  A short circuit in an electrical circuit that allows a current to travel along an unintended path, often where essentially no electrical impedance is encountered....
  
   — open circuit
  Open circuit
  The term Open circuit may refer to:*Open-circuit scuba, a type of SCUBA-diving equipment where the user breathes from the set and then exhales to the surroundings without recycling the exhaled air...
  
  
• Kirchhoff's current law — Kirchhoff's voltage law.
• Thévenin's theorem
  Thévenin's theorem
  In circuit theory, Thévenin's theorem for linear electrical networks states that any combination of voltage sources, current sources, and resistors with two terminals is electrically equivalent to a single voltage source V and a single series resistor R. For single frequency AC systems the theorem...
  
   — Norton's theorem
  Norton's theorem
  Norton's theorem for linear electrical networks, known in Europe as the Mayer–Norton theorem, states that any collection of voltage sources, current sources, and resistors with two terminals is electrically equivalent to an ideal current source, I, in parallel with a single resistor, R...
  
  

Constitutive relations

• Resistor and conductor (Ohm's law)

• Capacitor and inductor – differential form

• Capacitor and inductor – integral form

Voltage division — current division

Impedance and admittance

• Resistor and conductor

• Capacitor and inductor

See also

• Duality (electricity and magnetism)
• Duality (mechanical engineering)
  Duality (mechanical engineering)
  In mechanical engineering, many terms are associated into pairs called duals. A dual of a relationship is formed by interchanging force and deformation in an expression.Here is a partial list of mechanical dualities:...
  
  
• Dual impedance