Conductors Sentence Examples
The conductors are enclosed in a lead pipe, 24 in.
The neutralizing conductors for each disk are placed at right angles to each other.
Compared with nonmetallic solids, they in general are good conductors of heat and of electricity.
Conductors and engineers do get very tired and go home to rest.
In some cases the value of this electromotive force between two points or conductors is independent of the precise path selected, and it is then called the potential difference (P.D.) of the two points or conductors.
Measurement of Capacity.-Numerous methods have been devised for the measurement of the electrical capacity of conductors in those cases in which it cannot be determined by calculation.
Branly was the first to investigate and describe in 1890 the fact that an electric spark at a distance had the power of changing loose aggregations of metallic powders from poor to good electric conductors, and he also found that in some cases the reverse action was produced.
Materials like metal and water through which electric current (electricity) travels easily are called conducting materials or conductors.
Clerk Maxwell demonstrated, however, that all electric charge or electrification of conductors consists simply in the establishment of a physical state in the surrounding insulator or dielectric, which state is variously called electric strain, electric displacement or electric polarization.
For since electricity tends to move between points or conductors at different potentials, if the electricity is at rest on them the potential must be everywhere the same.
AdvertisementThe water flows from the ditches as conductors into built conduits formed at right angles to them in parallel lines through the fields; it rises upwards in them as high as the surface of the ground, and again subsides through the soil and the conduits into the ditches as main drains, and thence it passes at a lower level either into a stream or other suitable outfall.
The suppression of the Encyclopedie, to which he had been a considerable contributor, and whose conductors were his intimate friends, drew from him a shower of lampoons directed now at "l'infame" (see infra) generally, now at literary victims, such as Le Franc de Pompignan (who had written one piece of verse so much better than anything serious of Voltaire's that he could not be forgiven), or Palissot (who in his play Les Philosophes had boldly gibbeted most of the persons so termed, but had not included Voltaire), now at Freron, an excellent critic and a dangerous writer, who had attacked Voltaire from the conservative side, and at whom the patriarch of Ferney, as he now began to be called, levelled in return the very inferior farce-lampoon of L'Ecossaise, of the first night of which Freron himself did an admirably humorous criticism.
You also want the area around the conductors to dry thoroughly prior to loading new batteries into your equipment.
One of the frequent additions for the festival is guest conductors for both the BSO and the student orchestra.
Not only do these students have the opportunity to learn with leading professional musicians and conductors, but they also have the experiences of performing for large, adult audiences.
AdvertisementSnow and sand are both highly reflective conductors of the sun's rays.
The availability of the energy of electrical separation in a charged Leyden jar is also limited only by the resistance of conductors, in virtue of which an amount of heat is necessarily produced, which is greater the less the time occupied in discharging the jar.
In all cases there is a general tendency for other forms of energy to be transformed into heat on account of the friction of rough surfaces, the resistance of conductors, or similar causes, and thus to lose availability.
There is hardly one of Wagner's orchestral innovations which is not inseparably connected with his adaptation of music to the re q uirements of drama; and modern conductors, in treating Wagner's orchestration, as the normal standard by which all previous and contemporary music must be judged, are doing their best to found a tradition which in another fifty years will be exploded as thoroughly as the tradition of symphonic additional accompaniments is now exploded in the performances of Bach and Handel.
Between London and Birmingham a paper cable 116 m long and consisting of 72 copper conductors, each weighing 150 lb per statute mile, was laid in 1900.
AdvertisementThe peculiar action of electric sparks and waves in reducing the resistance of discontinuous conductors was rediscovered and investigated by Calzecchi Onesti,' by Branly, 2 Dawson Turner, 3 Minchin, Lodge, 4 and many others.
This seems to have been the first transmitter in which it was proposed to use the resistance at the contact of two conductors.
The electrostatic capacity of a cable of this type is low, and its dimensions are small, the external diameter of a cable containing 1600 ten-lb conductors being only 24 in.
The conductors used for subscribers' circuits are of copper weighing from 10 to 20 lb per mile.
Junction circuits are usually made up of 20 or 40 lb conductors.
AdvertisementThese may well serve as conductors of nervous impulses.
In this magnetic field is pivoted a small circular or rectangular coil carried in jewelled bearings, the current being passed into and out of the movable coil by fine flexible conductors.
Special commissioners were to have concurrent jurisdiction with the U.S. circuit and district courts and the inferior courts of Territories in enforcing the law; fugitives could not testify in their own behalf; no trial by jury was provided; i The precise amount of organization in the Underground Railroad cannot be definitely ascertained because of the exaggerated use of the figure of railroading in the documents of the "presidents" of the road, Robert Purvis and Levi Coffin, and of its many "conductors," and their discussion of the "packages" and "freight" shipped by them.
The strength of the current may also be regulated by introducing lengths of German silver or iron wire, carbon rod, or other inferior conductors in the path of the current, and a series of such resistances should always be provided close to the tanks.
The circulation of magnetic induction or flux through magnetic and non-magnetic substances, such as iron and air, is in many respects analogous to that of an electric current through good and bad conductors.
They pass through a viscous stage in cooling from a state of fluidity; they develop effects of colour when the glass mixtures are fused with certain metallic oxides; they are, when cold, bad conductors both of electricity and heat, they are easily fractured by a blow or shock and show a conchoidal fracture; they are but slightly affected by ordinary solvents, but are readily attacked by hydrofluoric acid.
When the furnace with this well-known regulating device was to be used, say, for the melting of metals or other conductors of electricity, the fragments of metal were placed in the crucible and the positive electrode was brought near them.
The rivalry was not without benefit to the literary public, as the conductors of each used every effort to improve their own review.
This shows that some bodies are conductors and others non-conductors or insulators of electricity, and that bodies can be electrified by friction and impart their electric charge to other bodies.
So far we have spoken of electric charge as if it resided on the conductors which are electrified.
From this fact it follows that we can shield any conductor entirely from external influence by other "charged conductors by enclosing it in a metal case.
Maxwell (Elementary Treatise, &c., p. 15) ingeniously applied this fact to the insulation of conductors.
The capacity of a conductor is defined to be the charge required to raise its potential to unity, all other charged conductors being at an infinite distance.
We now proceed to consider in more detail the laws which govern the distribution of electricity at rest upon conductors.
The first term on the right hand side expresses the energy of the surface electrification of the conductors in the field, and the second the energy of volume density (if any).
It is then a zero potential surface, and every point outside is at zero potential as far as concerns the electric charge on the conductors inside.
When a liquid undergoing evaporation is contained in a closed vessel, a molecule which has left the liquid will, after a certain 1 Other processes also help in the conduction of heat, especially in substances which are conductors of electricity.
Other notable conductors of the Weimar theatre orchestra were Eduard Lassen and Richard Strauss.
Electrostatic voltmeters are based on the principle that when two conductors are at different potentials they attract one another with a force which varies as the square of the potential difference (P. D.) between them.
This last point is important in connexion with voltmeters used on the switchboards of electric generating stations, where relatively strong electric or magnetic fields may be present, due to strong currents passing through conductors near or on the board.
This appointment was inaugurated by two events, - a course of eight lectures on sound, which proved no success and was not repeated, and the determination by means of a revolving mirror of the speed of electric discharge in conductors, a piece of work leading to enormously important results.
Thomson 6 places spherical bulbs inside thick spiral conductors through which the oscillating discharge of a powerful battery is led.
The case of electro-magnetic forces between two conductors carrying electric currents affords an example of a statement of motion in terms of force of a highly artificial kind.
Certain solvents, such as water, liquid ammonia or liquid hydrocyanic acid, possess the power of making some solutes, such as mineral salts and acids, when dissolved in them, conductors of electricity.
Aluminium conductors have been employed on heavy work in many places, and for telegraphy and telephony they are in frequent demand and give perfect satisfaction.
Iron pipes are the best conductors; they should lead to a capacious open reservoir placed outside the garden, and at the highest convenient level, in order to secure sufficient pressure for effective distribution, and so that the wall trees also may be effectually washed.
In their simplest form, they are merely a row of slender stakes of larch or other wood driven into the ground, and connected by a slight rod or fillet at top. The use of iron rails has now been almost wholly discontinued on account of metallic substances acting as powerful conductors of both heat and cold in equal extremes.
Some writers have supposed that the ultimate atoms are conductors, and that heat is transferred through them when they are in contact.
Weber's hypothesis of electric atoms, capable of diffusing through metallic bodies and conductors of electricity, but capable of vibration only in non-conductors, it is possible that the ultimate mechanism of conduction may be reduced in all cases to that of diffusion in metallic bodies or internal radiation in dielectrics.
This assumption does not present serious errors in the case of bad conductors, such as glass or wood, but has given rise to large mistakes in the case of metals.
It is the most convenient method, in the case of good conductors, on account of the great facilities which it permits for the measurement of the temperature gradient at different points; but it has the disadvantage that the results depend almost entirely on a knowledge of the external heat loss or emissivity, or, in comparative experiments, on the assumption that it is the same in different cases.
Unfortunately the method cannot be applied to good conductors, like the metals, because the difference of temperature between the surfaces may be five or ten times less than that between the water and steam in contact with them, even if the water is ener-, TABLE I.
This may be regarded as a variety of the plate method, but is more particularly applicable to good conductors, which require the use of a thick plate, so that the temperature of the metal may be observed at different points inside it.
To effect a remodelling when the ground is in stubble, let it be ploughed up, harrowed, and cleaned as in a summer fallow, the levelling-box employed when required, the stuff from the conductors and main drains spread abroad, and the beds ploughed into shape - all operations that can be performed at little expense.
The water should be let on, and trial made of the work, whenever it is finished, and the motion of the water regulated by the introduction of a stop in the conductors and feeders where a change in the motion of the current is observed, beginning at the upper end of the meadow.
They act the part of conductors when the land is to be flooded, and of main drains when it is to be laid dry.
Lowell himself had already turned his studies in dramatic and early poetic literature to account in another magazine, and continued the series in The Pioneer, besides contributing poems; but after the issue of three monthly numbers, beginning in January 1843, the magazine came to an end, partly because of a sudden disaster which befell Lowell's eyes, partly through the inexperience of the conductors and unfortunate business connexions.
The bad conductors take so long to reach a steady state that the rate of loss of heat at any moment depends on the past history more than on the temperature of the calorimeter at the moment.
The second dates from Volta's discovery to the discovery by Faraday in 1831 of the induction of electric currents and the creation of currents by the motion of conductors in magnetic fields, which initiated the era of modern electrotechnics.
In 1729 Gray made the important discovery that some bodies were conductors and others nonconductors of electricity.
Jean Theophile Desaguliers (1683-1744) announced soon after that electrics were non-conductors, and conductors were nonelectrics.
He showed that all substances could be electrified by friction, but that to electrify conductors they must be insulated or supported on non-conductors.
Having thus succeeded in drawing the electric fire from the clouds, Franklin conceived the idea of protecting buildings from lightning by erecting on their highest parts pointed iron wires or conductors communicating with the ground.
The electricity of a hovering or a passing cloud would thus be carried off slowly and silently; and if the cloud was highly charged, the lightning would strike in preference the elevated conductors.'
About the same time that Franklin was making his kite 1 See Sir Oliver Lodge, " Lightning, Lightning Conductors and Lightning Protectors," Journ.
He made many measurements of the electric conductivity of different solids and liquids, by comparing the intensity of the electric shock taken through his body and various conductors.
He showed that all conductors liquid and solid might be divided into two classes which he called respectively conductors of the first and of the second class, the first embracing metals and carbon in its conducting form, and the second class, water, aqueous solutions of various kinds, and generally those now called electrolytes.
Arago's previous investigations in the new science of electromagnetism, and crowned that labour by the announcement of his great discovery of the dynamical action between conductors conveying the electric currents.
Ampere in this paper gave an account of his discovery that conductors conveying electric currents exercise a mutual attraction or repulsion on one another, currents flowing in the same direction in parallel conductors attracting, and those in opposite directions repelling.
These investigations led him to the announcement of the fundamental law of action between elements of current, or currents in infinitely short lengths of linear conductors, upon one another at a distance; summed up in compact expression this law states that the action is proportional to the product of the current strengths of the two elements, and the lengths of the two elements, and inversely proportional to the square of the distance between the two elements, and also directly proportional to a function of the angles which the line joining the elements makes with the directions of the two elements respectively.
These experiments furnished the first elementary forms of electric motor, since it was then seen that rotatory motion could be produced in masses of metal by the mutual action of conductors conveying electric current and magnetic fields.
He proved by systematic experiments that the electromotive forces set up in conductors by their motions in magnetic fields or by the induction of other currents in the field were due to the secondary conductor cutting lines of magnetic force.
In the 9th series (1834) he announced the discovery of the important property of electric conductors, since called their self-induction or inductance, a discovery in which, however, he was anticipated by Joseph Henry in the United States.
The neutral fluid could, however, be divided up or separated into its two constituents, and these could be accumulated on separate conductors or non-conductors.
Plana (1781-1846), and later Robert Murphy (1806-1843), made them the subject of their investigations on the mode in which electricity distributes itself on conductors when in equilibrium.
Electromotive force is due to a difference in the density of the electronic population in different or identical conducting bodies, and whilst the electrons can move freely through so-called conductors their motion is much more hindered or restricted in non-conductors.
Under the series system only the first anode and the last cathode are connected to the conductors; between these are suspended, isolated from one another, a number of intermediate bi-polar electrode plates of raw copper, each of these plates acting on one side as a cathode, receiving a deposit of copper, and on the other as an anode, passing into solution; the voltage between the terminals of the tank will be as many times as great as that between a single pair of plates as there are spaces between electrodes in the tank.
The large demand for copper to be used in sheathing ships ceased on the introduction of iron in shipbuilding because of the difficulty of coating iron with an impervious layer of copper; but the consumption in the manufacture of electric apparatus and for electric conductors has far more than compensated.
Suppose it is required to measure the difference of potentials V and V' of two conductors.
If W is the weight required to depress the attracted disk into the same sighted position when the plates are unelectrified and g is the acceleration of gravity, then the difference of potentials of the conductors tested is expressed by the formula V - V'=(d - d') /87 W where S denotes the area of the attracted disk.
When the instrument is to be used to determine the potential difference between two conductors, they are connected to the two opposite pairs of quadrants.
A few months after his return, through Germany, to London in 1815, he was induced to take up the question of constructing a miner's safety lamp. Experiments with samples of fire-damp sent from Newcastle soon taught him that "explosive mixtures of mine-damp will not pass through small apertures or tubes"; and in a paper read before the Royal Society on the 9th of November he showed that metallic tubes, being better conductors of heat, were superior to glass ones, and explained that the heat lost by contact with a large cooling surface brought the temperature of the first portions of gas exploded below that required for the firing of the other portions.
One of the earliest was devoted to electrical conduction in a thin plate, and especially in a circular one, and it also contained a theorem which enables the distribution of currents in a network of conductors to be ascertained.
An urban council cFQ ' may also license proprietors, drivers and conductors of horses, ponies, mules or asses standing for hiring in the district in the same way as in the case of hackney carriages, and they may also license pleasure boats and vessels, and the boatmen or persons in charge thereof, and they may make by-laws for all these purposes.
Christie, in 1833.1 The arrangement of the six conductors is diagrammatically repre sented in fig.
To prove this statement, let the conductors P, Q, R, S., be arranged in a lozenge shape, as in fig.
The Kelvin bridge consists of nine conductors joining six points, and in one practical form is known as a Kelvin and Varley slide.
For the conductors among you, Management skills are a must these days - I am a strict adherent to the Dilbert principles!
He is tall and jovial and rather burly as conductors go, the possessor of almost as many curls as Simon Rattle.
The greater strengths of its 1.5 sq mm perfectly circular solidcore conductors provide the solution to this problem.
Here they consist of stranded conductors twisted together and housed in a PVC covering.
The Stratus 5 employs oxygen-free copper conductors and brass contacts.
Yuri Temirkanov is one of the world's most distinguished conductors and musicians.
Arrows represent the level of current reached at the length of 10000 grains for the corresponding filamentary coated conductors presented in two figures above.
In addition, philharmonic concerts from world-famous conductors form a sizeable part of the Opera House's repertoire.
There are nearly always three lightning conductors sticking up at the top of the tower.
All the new bi-wire cables in the Original Range feature an enhanced geometry that minimizes cable inductance by precisely spacing opposing sets of conductors.
And working with the great conductors - I got to play timpani in Mahler's Ninth Symphony with Claudio Abbado.
Geitel (7) that even the most perfectly insulated conductors lose their charge, and that this loss depends on atmospheric conditions.
St Elmo's Fire.-Luminous discharges from masts, lightning conductors, and other pointed objects are not very infrequent, especially during thunderstorms. On the Sonnblick, where the phenomenon is common, Elster and Geitel (87) have found St Elmo's fire to answer to a discharge sometimes of positive sometimes of negative electricity.
The reason why the whole of the energy of the current is not available is that heat must always be generated in a wire in which a finite current is flowing, so that, in the case of a battery in which the whole of the energy of chemical affinity is employed in producing a current, the availability of the energy is limited only on account of the resistance of the conductors, and may be increased by diminishing this resistance.
On the 4th of April 1877 Emile Berliner filed a caveat in the United States patent office, in which he stated that, on the principle of the variation with pressure of the resistance at the contact of two conductors, he had made an instrument which could be used as a telephone transmitter, and that, in consequence of the mutual forces between the two parts of the current on the two sides of the point of contact, the instrument was capable of acting as a receiver.
The heat makes itself evident by raising the temperature and therefore elongating the wire, whilst the magnetic field creates mechanical forces which act on pieces of iron or other conductors conveying electric currents when placed in proximity to the conductor in question.
The metals are mostly bodies of high specific gravity; they exhibit, when polished, a peculiar brilliancy or metallic lustre, and they are good conductors of heat and electricity; the nonmetals, on the other hand, are mostly bodies of low, specific gravity, and bad conductors of heat and electricity, and do not exhibit metallic lustre.
Miscellaneous Effects Of Magnetization Electrical Conductivity.-The specific resistance of many electric conductors is known to be temporarily changed by the action of a magnetic field, but except in the case of bismuth the effect is very small.
Suppose that we have any distribution of electricity at rest over conductors, and that we know the potential at all points and consequently the level or equipotential surfaces.
Only silver, copper and gold surpass it as conductors of heat, its value being 31.33 (Ag=10o, Roberts-Austen).
In the case of conductors of the first class he proved by the use of the condensing electroscope, aided probably by some form of multiplier or doubler, that a difference of potential (see Electrostatics) was created by the mere contact of two such conductors, one of them being positively electrified and the other negatively.
The French mathematicians, Coulomb, Biot, Poisson and Ampere, had been content to accept the fact that electric charges or currents in conductors could exert forces on other charges or conductors at a distance without inquiring into the means by which this action at a distance was produced.
As he was being led up to some object he noticed a hesitation and uncertainty among his conductors.
Since then he has performed as a soloist with many of the world 's major orchestras and most renowned conductors.
And working with the great conductors - I got to play timpani in Mahler 's Ninth Symphony with Claudio Abbado.
Music teachers and conductors can make suggestions that will help you find the right instrument to meet your needs.
Track lighting is a lighting system where small light fixtures are attached at intervals along a continuous track that contains electrical conductors.
The conductors are then twisted in pairs with definite lays.
The micas are bad conductors of heat and electricity, and it is on these properties that many of their technical applications depend.
The guides or conductors in the pit may be constructed of wood, in which case rectangular fir beams, about 3 by 4 in., are used, attached at intervals of a few feet to buntons or cross-beams built into the lining of the pit.
Edward Nairne's electrical machine (1787) consisted of a glass cylinder with two insulated conductors, called prime conductors, on glass legs placed near it.
Following the nomenclature usual in connexion with dynamos we may speak of the conductors which carry the initial charges as the field plates, and of the moving conductors on which are induced the charges which are subsequently added to those on the field plates, as the carriers.
If two Leyden jars L, L were hung upon the conductors which supported the combs, with their outer coatings put in connexion with one another by M, a series of strong spark discharges passed between the discharge balls.
When two metallic conductors are placed in an electrolyte, a current will flow through a wire connecting them provided that a difference of any kind exists between the two conductors in the nature either of the metals or of the portions of the electrolyte which surround them.