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, …

Read More »## 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 …

Read More »## 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 …

Read More »## 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 …

Read More »## 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 …

Read More »## 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 …

Read More »## 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 …

Read More »## Magnetic Flux Definition and Unit

Magnetic Flux is defined as; “a total number of lines of magnetic force passing through any surface placed perpendicular to the magnetic field. It is denoted by φ (Greek Letters Phi). Magnetic Flux Formula The magnetic flux is also defined as the dot product of magnetic field B and vector Area …

Read More »## Potentiometer Variable Resistor Working Principle

A potentiometer or a rheostat is an instrument used to measure and compare potentials without drawing any current from the circuit. Potentiometer Principle The potential difference across any length of wire of uniform cross-section area is directly proportional to its length where a constant current flows through it. A potentiometer consists …

Read More »## Magnetomotive Force (MMF) Definition

Magnetomotive force is defined as, “The force produced by current through a coil of wire is called magnetomotive force (mmf), as shown in the following figure. It is the force by which a magnetic field is produced. Just as an increase in electromotive force produces more current in a circuit, …

Read More »## Wheatstone Bridge Circuit Theory and Working Principle

Wheatstone bridge is used to measure unknown resistance and is defined by the circuit of the following figure. In above Figure, R1, R2, and R3 are known resistances and Rx is the resistance whose value is to be determined. At least one of the known resistances is variable. The variable resistance is …

Read More »## 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, …

Read More »## Magnetic Force on a Current Carrying Conductor

A current carrying conductor produces its own magnetic field. Such a conductor is placed in a magnetic field. The magnetic field of the conductor will interact with the external magnetic field. As a result of which the conductor may experience a force. It can be observed by the following experiment. …

Read More »## 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 …

Read More »## AC Energy Meter Working Principle

Energy is the product of power and time and is measured in watt-seconds or Joule. Since the voltage and current in a DC circuit are constant values, the energy is easily computed from a measurement of power and time, $W=Pt~~~~~~~~~~Joule$ Where W is in watt-seconds or Joules, P in watts …

Read More »