Even a permanent magnet is susceptible of induction, its polarity becoming thereby strengthened, weakened, or possibly reversed.
A small permanent magnet is always liable to become demagnetized, or have its polarity reversed by the action of lightning.
The first part of the epistle deals generally with magnetic attractions and repulsions, with the polarity of the stone, and with the supposed influence of the poles of the heavens upon the poles of the stone.
Tyndall's first original work in physical science was in his experiments with regard to magnetism and diamagnetic polarity, on which he was chiefly occupied from 1850 to 1855.
(25) Unless the path of the induction is entirely inside the metal, free magnetic poles are developed at those parts of the metal where induction enters and leaves, the polarity being south at the entry and north at the exit of the flux.
Weber's theory, the molecules of a ferromagnetic metal are small permanent magnets, the axes of which under ordinary conditions are turned indifferently in every direction, so that no magnetic polarity is exhibited by the metal as a whole; a magnetic force acting upon the metal tends to turn the axes of the little magnets in one direction, and thus the entire piece acquires the properties of a magnet.
This great event was preceded by the general Portu- utilization in Europe of the polarity of the magnetic guese ex- needle in the construction of the mariner's compass.
He also found that the polarity which minerals receive from heat has a relation to the secondary forms of their crystals - the tourmaline, for example, having its resinous pole at the summit of the crystal which has three faces.
The Arabic geographer, Edrisi, who lived about r roo, is said by Boucher to give an account, though in a confused manner, of the polarity of the magnet (Hallam, Mid.
Amongst the most important of his works not already mentioned may be named the following: - Mathematical Tracts (1826) on the Lunar Theory, Figure of the Earth, Precession and Nutation, and Calculus of Variations, to which, in the second edition of 1828, were added tracts on the Planetary Theory and the Undulatory Theory of Light; Experiments on Iron-built Ships, instituted for the purpose of discovering a correction for the deviation of the Compass produced by the Iron of the Ships (1839); On the Theoretical Explanation of an apparent new Polarity in Light (1840); Tides and Waves (1842).
Further, the eye is endowed with polarity, by which its activity is divided into two parts qualitatively distinct.
When Clerk Maxwell pointed out the way to the common origin of optical and electrical phenomena, these equations naturally came to repose on an electric basis, the connexion having been first definitely exhibited by FitzGerald in 1878; and according as the independent variable was one or other of the vectors which represent electric force, magnetic force or electric polarity, they took the form appropriate to one or other of the elastic theories above mentioned.
The most interesting of his discoveries, now generally known as the " Wiedemann effect," is the following: If we magnetize longitudinally a straight wire which is fixed at one end and free at the other, and then pass an electric current through the wire (or first pass the current and then magnetize), the free end of the wire will twist in a certain direction depending upon circumstances: if the wire is of iron, and is magnetized (with a moderate force) so that its free end has north polarity, while the current through it passes from the fixed to the free end, then the free end as seen from the fixed end will twist in the direction of the hands of a watch; if either the magnetization or the current is reversed, the direction of the twist will be reversed.
T Malus gave the name of polarization, as he attributed it, on the emission theory of light, to a kind of polarity of the light-corpuscles.
He quotes a passage on the polarity of the lodestone from a treatise translated by Albertus Magnus, attributed by the latter to Aristotle, but apparently only an Arabic compilation from the works of various philosophers.
The wire will in fact become temporarily magnetized by induction, that end of it which is nearest to the pole of the magnet acquiring opposite polarity, and behaving as if it were the pole of a permanent magnet.
- Noticing an analogy between the polarity of the voltaic pile and that of the magnet, philosophers had long been anxious to discover a relation between the two, but twenty years elapsed after the invention of the pile before Hans Christian Oersted (1777-1851), professor of natural philosophy in the university of Copenhagen, made in 1819 the discovery which has immortalized his name.
This theory of complementary colours as due to the polarity in the qualitative action of the retina is followed by some criticism of Newton and the seven colours, by an attempt to explain some facts noted by Goethe, and by some reference to the external stimuli which cause colour.
Ampere had already previously shown that a spiral conductor or solenoid when traversed by an electric current possesses magnetic polarity, and that two such solenoids act upon one another when traversed by electric currents as if they were magnets.
Might we eventually return to the iniquitous polarity of a land-owning gentry v the serfs?
The old doctrine of types, which was used by the philosophically minded zoologists (and botanists) of the first half 1 A very subtle and important qualification of this generalization has to be recognized (and was recognized by Darwin) in the fact that owing to the interdependence of the parts of the bodies of living things and their profound chemical interactions and peculiar structural balance (what is called organic polarity) the variation of one single part (a spot of colour, a tooth, a claw, a leaflet) may, and demonstrably does in many cases entail variation of other parts - what are called correlated variations.
Yet it will be magnetized; for if it is cut through and the cut ends are drawn apart, each end will be found to exhibit polarity.
Everything I've said here can be understood in terms of the polarity of precision and meaning discussed in the previous article.
If the polarity of the voltage is reversed the current changes direction but its size is unchanged.
electromagnetic ' smog ' can affect all biological systems by disorientating their positive polarity field.
Reverse Polarity Protection is built into the beacon and achieved with negligible power loss by using a FET instead of a diode.
Polarity is clearly seen in Vibrio cholerae, a highly motile pathogen that swims by rapidly rotating a single polar flagellum.
Also included within this test is a polarity and earth fault loop impedance test of up to 10% of the sockets.
Secondly, it decreases the open flux by increasing the length of the polarity inversion line where flux cancelation occurs.
polarity of the molecule, the boiling point has only been increased by some 10° .
In fact the field has reversed polarity many times.
follow the polarity (+/-) diagram in the battery compartment.
You again get a polar molecule, although with a reversed polarity from the first example.
These produce a uniform electric field between the plates of opposite polarity.
reverse polarity of 400 Vp may be applied across the output leads indefinitely.
But he did find that the magnetic polarity was the opposite of the Earth's present magnetic field.
To support or challenge a claim, one uses relations with either positive or negative polarity.
Connect a suitable power supply being sure to observe correct polarity.
polarity inversion line where flux cancelation occurs.
polarity reversal protection.
polarity therapists will often help clients to become more aware of these areas which are detrimental to their health.
We found no significant increase in the detection efficiency for either radioisotope with the MCP bias polarity reversed.
Note: If you aren't sure about electronegativity and bond polarity follow this link before you read on.
Epithelial planar cell polarity refers to situations in which cells become polarized within the plane of an epithelium.
Ulysses reached maximum southern latitudes in late 2000, before solar polarity reversal had occurred.
reversepan>reversing the polarity of the voltage, the atoms can be re-deposited anywhere on the silicon surface.
soluble in the usual organic solvents of low polarity.
They are quite soluble in the usual organic solvents of low polarity.
Thus in A the twist may be right-handed or left-handed; in B the polarity of a given end may become north or south; in C the circular magnetization may be clockwise or counter-clockwise; in D the length may be increased or diminished; in E the magnetization may become stronger or weaker.
the magnet at sea; 2 and before the middle of the r3th century Gauthier d'Espinois alludes to its polarity, as if generally known, in the lines: "Tous autresi comme l'aimant decoit [detourne] L'aiguillette par force de vertu, A ma dame tor le mont [monde] retenue Qui sa beaute connoit et apercoit."
By reversing the polarity of the voltage, the atoms can be re-deposited anywhere on the silicon surface.
This voltage has opposite polarity to the supply voltage on the coil.
Most thermal vision goggles or binoculars are fairly compact for ease of use and also offer adjustable focus and selectable polarity.
As centuries passed the concept of ying and yang, commonly referred to as yin yang, evolved to represent the Chinese philosophy of the dual polarity and balance of everything in the universe.
This constant ebb and flow of energy, or constant change, relates to the yin yang concept of polarity.
The yin yang concept of polarity is a balance of energetic forces.
The complex philosophies of the yin yang concepts may change based on Daoism, Buddhism or the western culture, but the basic concepts of polarity, duality, infinity and balance of yin yang theory remains the same throughout belief systems.
This question arises if the person is unfamiliar with the powerful symbol that embodies the essence of the ancient Chinese philosophy of the dual polarity of everything in the universe.
As each sign alternates, they also reflect a polarity (positive/negative, yin/yang and masculine/feminine).
This pairing exemplifies two strong signs whose polarity works to attract, and then to drive them apart eventually.
Orange sits just above red as the polarity chakra.
The word usage examples above have been gathered from various sources to reflect current and historial usage. They do not represent the opinions of YourDictionary.com.