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# Basic Electrical

## Inductor Types and Symbols

In spite of the great number of different kinds of inductors, only a few schematic symbols are needed to represent them. Filter Choke A filter choke for a power supply is shown in figure 1 (a), and its symbol is shown in figure 1(b). Fig.1: Iron Core Choke Coil: (a) …

## RL Circuit Time Constant | Universal Time Constant Curve

When a series RL circuit is connected across a supply, voltage and current transients occur until the current attains a steady-state condition. Consider the circuit figure 1, where R represents the coil’s resistance or an external resistance. When the switched is closed, current begins to flow into the inductance. The …

## RC Circuit Time Constant | Charging Discharging of Capacitor

Definition:The time required to charge a capacitor to about 63 percent of the maximum voltage in an RC circuit is called the time constant of the circuit.   When a discharged capacitor is suddenly connected across a DC supply, such as Es in figure 1 (a), a current immediately begins …

## Capacitor Types | Fixed and Variable Capacitors

Variable capacitors Variable capacitors are distinguished by the fact that their capacitance can be changed. Basically, there are two most common types of such capacitors named as a trimmer and rotor-stator capacitors. Rotor-Stator Capacitor The rotor-stator type of capacitor comprises two metallic plate sets. The moving plates are attached conjointly …

## Ohm’s Law | Definition | Formula | Applications

Ohm’s Law Definition Ohm’s law states that the current in an electric circuit is proportional to the applied voltage and inversely proportional to its resistance. As the voltage increases in a circuit (resistance remaining constant), the current increases by the same amount. Hence, if the voltage is doubled, the current …

## Capacitive Reactance in AC Circuit

Capacitive Reactance The AC Current flow in a capacitor depends on the supply voltage and the capacitive reactance. The capacitance value and the supply frequency determine the capacitive reactance. The alternating current through a capacitor leads the capacitor terminal voltage by 90o as shown in the figure below. If a …

## Inductive Reactance in AC Circuit

Inductive Reactance Alternating current flow in an inductor depends on the applied voltage and on the inductive reactance of the inductor. The inductive reactance is proportional to the inductance value and the frequency of the alternating supply voltage. When an alternating voltage is applied to a pure inductance, the current …

## 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 …

## Factors Affecting Capacitance | Dielectric Constant

There are three main factors affecting the capacitance of the capacitors that will be discussed in this tutorial in detail. 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. capacitance is the ability …

## Types of Resistors

Resistors can be classified into different types according to their construction.  Wire-wound resistors are made by wrapping high-resistance wire around an insulated cylinder, as illustrated in Figure 1. This type of resistor is generally used in circuits that carry high currents. Large wire-wound resistors are called power resistors and range in size from ½ …

## Nonlinear Resistors | Characteristics Curves of Nonlinear Devices

In most circuits, we can assume that resistance is constant in relation to current and voltage. This linear relation can be graphically shown in figure 1. Fig.1: Plot of Linear Relation between Current and Voltage For example, if 3V is applied to a certain resistor and 1A flows, then 6V …

## How to Read Resistor Color Code | Resistor Color Bands

Carbon resistors are color coded- that is, they have several color bands painted around the body near one end- to identify their ohmic values. Other types of resistors are not color-coded; instead, they have their ohmic values and, sometimes, identifying part numbers printed on them. The code has been established by …

## Resistor Power Rating | Power resistor

The physical size of a resistor is not determined by its resistance but by how much power, or heat, it can dissipate. It electric circuits, the unit of power is the watt (W), named in honor of James Watt. One watt is the power dissipated when one ampere flows under …

In analyzing a series circuit, it becomes necessary to find voltage drop across one or more of the resistances. A simple voltage drop relationship may be obtained by referring to the following figure. The total current is given by, $I=\frac{E}{{{R}_{1}}+{{R}_{2}}+{{R}_{3}}}$ And the voltage drop are given by, \${{V}_{1}}=I{{R}_{1}}=E\frac{{{R}_{1}}}{{{R}_{1}}+{{R}_{2}}+{{R}_{3}}}~~~~\text{  }~~~\left( 1 …