Compared with nonmetallic solids, they in general are good conductors of heat and of electricity.
The neutralizing conductors for each disk are placed at right angles to each other.
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.
So far we have spoken of electric charge as if it resided on the conductors which are electrified.
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.
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.
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.
The 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.
The conductors are then twisted in pairs with definite lays.
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.
The conductors used for subscribers' circuits are of copper weighing from 10 to 20 lb per mile.
These may well serve as conductors of nervous impulses.
- Instruments of the third class depend for their action on the fact discovered by Ampere, that mechanical forces exist between conductors carrying electric currents when those conductors occupy certain relative positions.
Eilos, like), strictly belongs to certain elements which do not possess the properties of the true metals, although they more closely resemble them than the non-metals in many respects; thus, selenium and tellurium, which are closely allied to sulphur in their chemical properties, although bad conductors of heat and electricity, exhibit metallic lustre and have relatively high specific gravities.
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 micas are bad conductors of heat and electricity, and it is on these properties that many of their technical applications depend.
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).
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.
P y All these solutions are non-conductors of electricity.
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.
Only silver, copper and gold surpass it as conductors of heat, its value being 31.33 (Ag=10o, Roberts-Austen).
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.
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.
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.
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.
Other notable conductors of the Weimar theatre orchestra were Eduard Lassen and Richard Strauss.
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.
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.
- If there be any number of charged conductors in a field, the electrification on them being in equilibrium or at rest, the surface of each conductor is an equipotential surface.
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.
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.
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.
The rivalry was not without benefit to the literary public, as the conductors of each used every effort to improve their own review.
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.