## 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 …

## Comparison between Electrical and Magnetic Circuits

The most important differences between Electrical Circuit and Magnetic Circuit are discussed in this article on the basis of Exciting Force, Current & Flux Density, Lines of Force, Series & Parallel Circuit Behavior, Insulation, Energy, Temperature, and Circuits Representation. The following table keys out the main Differences between Electric and Magnetic …

## Hysteresis Loss | Eddy Current and Core Losses

The area within the hysteresis loop is a product of B and H and this area represents the energy per unit volume that must be used per magnetization cycle to move the domains.  Hysteresis Loss With appropriate constants, the hysteresis loss can be given in watts per unit volume. An …

## Hysteresis Loop | Magnetization Curve

Hysteresis Loop Definition A curve, or loop, plotted on B-H coordinates showing how the magnetization of a ferromagnetic material varies when subjected to a periodically reversing magnetic field, is known as Hysteresis Loop. Hysteresis Definition Hysteresis is the lagging of the magnetization of a ferromagnetic material behind the magnetizing force …

## 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. …

## Absolute and Relative Magnetic Permeability

Permeability is the measure of the ease, with which magnetic lines of force pass through a given material. The ability of a material to concentrate magnetic flux is called permeability and its symbol is the Greek lower case letter μ. Any material that is easily magnetized tends to concentrate magnetic …

## Magnetic Field Intensity | Definition Formula

Magnetomotive force, ℑ , per unit length, is called the magnetic field intensity H. Magnetic Field Intensity Unit Magnetic field intensity is also known as the magnetizing force which is measured is ampere-turns per meter (A-t/m). Of primary concern, however, is the magnetomotive force needed to establish a certain flux density, …

## Magnetic Flux Density | Definition and Formula

Magnetic Flux Density Flux density is the measure of the number of magnetic lines of force per unit of cross-sectional area. While the total amount of the flux produced by a magnet is important, we are more interested in how dense or concentrated, the flux is per unit of cross-sectional …

## 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 …

## Digital Voltmeter Circuit and Working Principle

In digital voltmeters, input quantity is a voltage or is converted into a voltage. Normally, digital voltmeters are abbreviated as DVM. The process by which a DVM converts the analog input into digital output is known as analog to digital conversion. The basic conversion processes are the comparison and voltage …

## Digital Frequency Meter Circuit Diagram and Working Principle

The frequency of periodic electric voltage or current can be determined directly by the use of a frequency meter or indirectly through a comparison with a known frequency. One of the many frequency meters that directly indicates frequency is reed –type meter of the following figure. Fig.1: (a) Reed-Type Meter …

## Oscilloscope Basics | What is an Oscilloscope

“Oscilloscope is most widely used to display amplitude and period of the signal as well as the shape of the wave.” Anything can be measured on the two-dimensional graph drawn by an oscilloscope. Normally, voltage is displayed on the vertical, or Y-axis and time on the horizontal, or X axis …