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# Basic Electrical

## Impedance, Inductive Reactance and Capacitive Reactance

Impedance is the combined resistance in the flow of current because of resistive and reactive elements in the circuit. It is measured is ohm and calculated as follows; $Z=R+jX$ Inductive Reactance Consider a sinusoidal current to be flowing in the pure inductance as shown in the following Fig. that is …

## Power Factor Correction using Capacitor Bank

Power factor Ideally, all the supply voltage and current should be converted into true power in a load. When this is not a case, a certain kind of inefficiency occurs. The ratio of true power to apparent power is called the power factor of the load, \[\begin{matrix}   Power\text{ }Factor=\frac{true\text{ }Power}{Apparent\text{ …

## Apparent, Active and Reactive Power

This section covers basic concepts about apparent, active (real) and reactive power which is important ingredients in the analysis of a power system. Consider the general single-phase circuit with a sinusoidal voltage $v={{V}_{m}}sin\left( wt \right)$ applied. A current $i={{I}_{m}}sin(wt\pm \theta )$  results and is leading (θ is positive) for a capacitive …

## Maximum Power Transfer Theorem

Maximum Power Transfer Theorem Definition Maximum power transfer theorem states that maximum power output is obtained when the load resistance RL is equal to Thevenin resistance Rth as seen from load Terminals. Fig.1: Maximum Power Transfer Theorem Any circuit or network may be represented by a Thevenin equivalent circuit.  The Thevenin …

## Nodal Analysis or Node voltage Method

Nodal analysis or Node voltage method uses node voltages as circuit variables in order to analyze the circuit. The objective of this section is to obtain a set of simultaneous linear equations. However, unlike the mesh analysis method, the procedure developed in this section depends on the choice of certain …

## Mesh Current Analysis | Mesh Analysis

The mesh is a closed path which does not contain any other closed path within it. This section shows that a set of simultaneous linear equations can be written which describes the network. This set of equations depends on a choice of loop currents used in connection with Kirchhoff’s law. …

## Kirchhoff’s Voltage Law (KVL)

In order to present Kirchhoff’s voltage law, we must introduce the concept of a “loop”. Since energy must be conserved when a charge goes around a loop, the energy given up by the charge equals the energy it gains. The same energy-conservation principle would apply if you carried a rock …

## Kirchhoff’s Current law (KCL)

For a given circuit, a connection of two or more elements is called a NODE. The particular circuit shown in figure 1 depicts an example of a node. Figure.1: Circuit for Kirchhoff’s Current Law We now present the Kirchhoff’s current law which is essentially the law of conservation of electric …

## RC Series Circuit Analysis | RC Time Constant

In the case of a resistive-capacitive (RC) series circuit, when the supply is first switched on the charging current is initially at its maximum level, then it gradually falls to zero. The capacitor voltage is zero at first and grows gradually to its maximum level. As with the RL Circuit, …

## Resistors in Series and Parallel

Resistance Resistance is defined as the measure of opposition to the motion of electrons due to their continuous collisions, with the atoms of the conductor. The unit of resistance is ohm. Let’s consider the conductor of cross-sectional area A and of length L as given below: The resistance of this …

## Capacitors in Series and Capacitors in Parallel

A capacitor is a passive device which stores energy in an electric field and opposes the change in voltage. An electric field can be created by placing two conducting plates in parallel and having one plate more positive than other as shown in fig. The material between two plates is …

## RL Series Circuit Analysis

When a resistive-inductive (RL) series circuit has its supply voltage switched on, the inductance produces an initial maximum level of counter-emf that gradually falls to zero. The circuit current is zero initially and grows gradually to its maximum level. The behavior of an RL series circuit is most easily understood …

## Inductors in Series and Parallel | Energy Stored in Inductor

In this section, we will calculate an equivalent inductance of inductors in series and inductors in parallel. Inductors in Series The method for determining the total inductance of the following circuit is similar to that used for series resistors. According to Kirchhoff’s voltage law, we can write following equation for the …