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# Definitions

## A

Average Value The sum of the instantaneous voltages in a half cycle wave shape divided by the number of instantaneous voltages. In a sine wave, it is equal to 0.637 times the peak voltage. Analog meters Analog meters are a multifunctional multimeter that operates based on electrical mechanical movement. Autotransformer A …

## B

Branch In a parallel circuit, each current path is a Branch. Band-Pass Filter A resonant circuit that is tuned to pass a single band of frequencies and to attenuate all other signals. Band-Rejection Filter A network that attenuates a single band of frequencies and allows those on either side to …

## C

Capacitance The property of a circuit that permits the storage of an electric charge when a difference of voltage is applied. Current Electric current is the rate of flow of charge in a conductor. Current Limiting Resistor A resistor inserted into an electric circuit to limit the current to some …

## D

Discrete Time System When the time variable t takes on the discrete values t=kT, k=…,-2,-1, 0, 1, 2… the system is said to be discrete – time system. Dependent Sources  Voltage or current source whose value linearly depends upon the value of voltage or current of other elements in the …

## E

Electromagnet An electromagnet is composed of a coil of wire wound around a core of a soft iron. Electron A negatively charged subatomic particle with much less mass than a proton but with a charge equal and opposite to the charge of a proton. Energy Energy is the capacity to …

## F

Farad The SI unit of capacitance is Farad, named in honor of the English physicist and chemist Michael Faraday. The unit symbol for the farad is F. Fuse A protective device containing a special wire that melts when excessive current passes through it, thereby opening the circuit. Filter A selective …

## G

Ground A conductor providing either a common return path to the voltage source or a zero reference point, which makes it possible to obtain positive or negative voltages (with respect to ground) from the same power supply. Gauss-Seidel method An iterative technique for solving a set of nonlinear equations (e.g., …

## H

Horse Power (HP) Horse Power is a measure of the work output of a motor (electrical or otherwise). The conversion from HP to watts is 1 HP = 746 Watts (Imperial Units). Hertz The SI unit of frequency; equal to one cycle per second. Henry The SI unit of inductance …

## I

Ideal transformer A transformer characterized by no winding resistance, no leakage ﬂux, and a lossless and inﬁnitely permeable magnetic core. Identity, or unit, matrix A diagonal matrix whose elements in the principal diagonal are all equal to unity and all elements not in the principal diagonal are equal to zero. …

## J

Joule (j) The SI unit of work.

## K

Kirchoff’s Current Law (KCL) KCL says that the algebraic sum of the currents arriving at and leaving any junction point is zero. Kirchoff’s Voltage Law (KVL) KVL states that the algebraic sum of all the voltage drops in a series circuit must equal the supply voltage.

## L

Lagging power factor  An operating power factor condition such that the phasor current lags the phasor voltage. Leading power factor  An operating power factor condition such that the phasor current leads the phasor voltage. Linear electromagnetic system An electromagnetic system whose flux linkages are expressed as linear combinations of the …

## M

Magnet A body that possesses the property of magnetism is called a magnet. Magnetism Magnetism is a property associated with materials that attract iron and iron alloys. Megohmmeter Megohmmeter commonly called a Megger®, is used to detect insulation failure within motors and transformers. Matter Any substance that has weight (mass) …