PHYSICS DICTIONARY

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z

 
<Prev>                   <Next>


Viscosity

 It is the property of a fluid which opposes the relative motion between its layers. Viscosity is known as fluid friction.

Visible Spectrum

 Molecular spectrum obtained in visible or ultraviolet region.

Vitrification

 During firing of a ceramic body, the formation of a liquid phase that upon cooling, becomes a glass bonding matrix.

VME

VME stands for Versa Module Europa. It was jointly introduced in 1981 by Mostek, Motorola, Phillips, and Thompson. The original motivation of VME development and standardization was to introduce modular approach to highly intense computing tasks. However it was quickly adopted by researchers in other fields as well, so much that it now probably stands as the most used system in research laboratories. Due to its flexibility and expandability, it has received its fair share of popularity in industrial environments as well. The original VME standard is now referred to as VME32 as it could handle up to 32 bits of data. The new standard is called VME64 and has the capability of 64 bit data transfers.

VME Logic

VME is a TTL based system. That is, its internal functioning follows TTL logic. However modules accepting and producing other logic signals can be integrated into the system.

Volt

It is the unit used to measure electric potential difference between two points. One volt is electric potential difference between two points when one joule of work is done in carrying one coulomb of positive charge from one point to another.

Voltage

It represents electric potential energy per unit charge. It is measurement of the energy contained within an electric field, or an electric circuit, at a given point.

Volume Strain

 It is the change in volume per unit original volume or it is the fractional change in volume.

Vulcanization

Non reversible chemical reaction involving sulphur or other suitable agent where in crosslink’s are formed between molecular chains in rubber materials. The rubber’s modulus of elasticity and strength are enhanced. 

VVER

 Acronym for Voda Vodyanoi Energitechesky reactor (water cooled water moderated energy reactor)

PHYSICS DICTIONARY

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z


<Prev>                   <Next>

Translucency

 It is the property of the substance transmitting light only diffusively; objects viewed through a translucent medium are not clearly distinguishable.

Transmission Electron Microscopy

The image seen with TEM is formed by electron beam that passes through specimen. Details of internal microstructure features are accessible to observation; contrasts in the image are produced by differences in beam scattering or diffraction produced between various elements of microstructure or defect. Since solid materials are highly absorptive to electron beams, a specimen to be examined must be prepared in the form of very thin foil; this ensures transmission through specimen of an appreciable fraction of incident beam. The transmitted beam is projected onto a fluorescent screen or a photographic film so that the image may be viewed. Magnifications approaching      106 times are possible with TEM, which is frequently utilized in study of dislocations.

Transmission

 It is property of a substance to permit the passage of light, with some or none of the incident light being absorbed in process.

Transmitting Power

 The ratio of amount of radiations transmitted by a body in a certain time to amount of radiations incident on it in the same time is called transmitting power.

Transverse Wave Motion

 Type of wave motion in which particles of medium vibrate at right angles to direction of propagation of wave.

Triple Point

The temperature and pressure combination for a substance at which liquid vapor curve, fusion curve and sublimation curve coincide. It is the combination at which substance coexists in solid, liquid and vapor phases.

Triton

Nucleus of Hydrogen-3 (1H3 ) atom, consists of one proton and two neutrons bound together with a total binding energy of 8.48 Mev. The H-3 atom, a radioactive isotope of hydrogen with a half life ty2 of 12.32 yrs, is called as Tritium and consists of a nucleus and one electron.

Tropopause

The boundary between the troposphere and the stratosphere is called the "tropopause", located at an altitude of around 5 miles in the winter, to around 8 miles high in the summer, and as high as 11 or 12 miles in the deep tropics. 

Troposphere

The troposphere is the lowest major atmospheric layer, extending from the Earth's surface up to the bottom of the stratosphere. The troposphere is where all of Earth's weather occurs. It contains approximately 80% of the total mass of the atmosphere. The troposphere is characterized by decreasing temperature with height (at an average rate of 3.5 oF per thousand feet, or

6.5 oC per kilometer).

Trough

The trough of a wave is the point at which particle has maximum amount of negative or downward displacement from the rest position.

Tuning Fork

 Arrangement of U–shaped rod attached to metal stem, used as a source of standard frequency. It is made of an alloy of Nickel and steel.

Tunnel Diode

A tunnel diode is a P-N junction where both P-and N-type regions are degenerately doped. As a result, the Fermi level in the N-type material is above the minimum of the conduction band and the Fermi level in the P-type material is below the maximum of the valence band. The doping concentrations are so high that the width of the space-charge region at the junction is extremely thin, and usually measures less than 10nm. The diode exhibits negative resistance characteristics.

Twin Boundaries

A twin boundary is a special type of grain boundary across which there is a specific mirror lattice symmetry; that is atoms on one side of boundary are located in mirror image positions of atoms on the other side. The region of material between these boundaries is approximately termed as a twin.

Twin Paradox (Relativity)

It is well known hypothetical concept in relativity under time dilation. As per this concept, one of two twins remains at rest and other moves in space ship moving with nearly velocity of light for some duration and come back. Applying theory of relativity, age of twin in space shuttle appears to be high. This leads to paradox.

Type-I Superconductor

Superconductor which exhibits complete Meissner effect for magnetic fields up to a limit is called critical magnetic field.

Type-II Superconductor

This type is discovered by Schubikov. Superconductor which exhibits Meissner effect till a particular magnetic field range, beyond which admits magnetic flux but retains zero resistance till a particular field value (critical field II) beyond which settles to normal state.