The Seebeck effect is a fundamental phenomenon in thermoelectricity, where a voltage (electromotive force, EMF) is generated across two dissimilar conductors or semiconductors when their junctions are maintained at different temperatures. This effect is the basis of thermocouples, widely used for temperature measurement and power generation. Discovered by Thomas Johann Seebeck in 1821. Physical Principle …
The Standing Wave Ratio (SWR) is a measure of how efficiently power is transmitted from a source to a load through a transmission line. It indicates the presence of standing waves due to impedance mismatch. Definition The standing wave ratio (SWR) is defined as the ratio of the maximum amplitude of the voltage (or current) …
A uniform plane wave (UPW) is a special type of electromagnetic wave in which the electric field and magnetic field are uniform over any plane perpendicular to the direction of propagation. It is an idealized concept widely used in wave propagation, transmission lines, and antenna theory. Definition A uniform plane wave is defined as an …
The loss tangent is an important parameter used to describe the energy loss in a dielectric material when it is subjected to an alternating electric field. It indicates how much of the electrical energy is dissipated as heat instead of being stored. Definition of Loss Tangent The loss tangent \( (\tan \delta) \) is defined …
Skin depth is an important concept in electromagnetics that describes how alternating current (AC) distributes within a conductor. At higher frequencies, current tends to concentrate near the surface of the conductor rather than flowing uniformly throughout its cross-section. This phenomenon is known as the skin effect. Definition of Skin Depth The skin depth (\( \delta …
The phase constant is an important parameter in wave propagation that describes how rapidly the phase of a wave changes with distance. It is commonly denoted by \( \beta \) and is also known as the phase propagation constant. Definition The phase constant (\( \beta \)) is defined as the rate of change of phase …
The phase velocity of a wave is the speed at which a particular phase point of the wave (such as a crest or trough) travels in space. It is an important concept in the study of wave propagation, transmission lines, and electromagnetic waves. Definition The phase velocity (\( v_p \)) is defined as the rate …
A three-phase transformer is an electrical device used to step up or step down three-phase voltage levels in power systems. It plays a vital role in generation, transmission, and distribution of electrical energy. Instead of using three separate single-phase transformers, a single three-phase transformer unit is often preferred due to its compact size, lower cost, …
The limiting error is an important concept in measurement systems that indicates the maximum possible error in a measurement. It helps define the accuracy and reliability of an instrument. Definition of Limiting Error The limiting error is defined as the maximum deviation of the measured value from the true value that an instrument can have …
The Normal Probability Curve (NPC), also known as the Gaussian distribution, is a fundamental concept in statistics and measurement theory. It is widely used to describe the distribution of random errors in measurements. In practical measurements, errors are unavoidable, and the normal probability curve helps in understanding how these errors are distributed. Mathematical Expression The …