## 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) …

## Electrical Formulas | Electrical Formulas Sheet

A Absolute Permittivity ${{\varepsilon }_{o}}=8.84*{{10}^{-12}}$ Active Power $\text{P=VICos(}\theta \text{) Watt}$ Apparent Power $\text{S=VI volt-amp}$ B C Capacitance $\text{C=}\frac{\text{ }\varepsilon {{\text{ }}_{\text{o}}}\text{ }\varepsilon {{\text{ }}_{\text{r}}}\text{A}}{\text{d}}$ Where, εo= Absolute Permittivity εr= Relative Permittivity A=Plates Area d= distance between plates Conductance $\text{Conductance}=\frac{1}{\text{Resistance}}=\frac{1}{\text{R}}$ Capacitive Reactance ${{\text{X}}_{\text{C}}}\text{=}\frac{1}{2\pi fC}$ Capacitive Susceptance ${{\text{B}}_{\text{C}}}\text{=}\frac{1}{{{\text{X}}_{\text{C}}}}$ Current in Series Circuit …

## N

Nyquist criterion The Nyquist criterion is a frequency domain tool which is used in the study of stability. To use this criterion, the frequency response data of a system must be presented as a polar plot in which the magnitude and the phase angle are expressed as a function of …

## O

Open-Loop Control System An open loop system is characterized by the fact that the input signed is processed without being affected by the output. Oscilloscope Oscilloscope is most widely used to display amplitude and period of the signal as well as the shape of the wave Ohm The unit of …

## P

Permeability Permeability is the measure of the ease, with which magnetic lines of force pass through a given material. Proton A positively charged particle with considerable mass. Phase rotation meter Phase rotation meter is a device used to determine the phase order of a three-phase electrical system. Parallel Circuit In …

## R

Reluctance  The opposition that a magnetic circuit presents to the passage of magnetic lines through it. Reactance The opposition to the flow of an alternating current by an inductive or capacitive element in the circuit. Resistance Resistance is defined as the measure of opposition to the motion of electrons due …

## S

SI unit SI units are most widely used units of measurement belong to an international system of units which is also known as SI or Metric System. Shunt A precision resistor connected in parallel with a current indicating meter for the purpose of bypassing a specific fraction of current around …