Ampere Sentence Examples
The application of this to telegraphic purposes was suggested by Laplace and taken up by Ampere, and afterwards by Triboaillet and by Schilling, whose work forms the foundation of much of modern telegraphy.
Currents from the ten-thousandth of an ampere to ten thousand amperes, electrical pressures from a minute fraction of a volt to 100,000 volts, come within the range of his instruments, while the private consumer of electric energy is provided with a meter recording Board of Trade units.
In the following year he was sent to study law at Paris, where he fell in with the Ampere family, and through them with Chateaubriand, Lacordaire, Montalembert, and other leaders of the neo-Catholic movement.
Ampere floated a voltaic battery with a coil of wire in its circuit in order to observe the effects of the earth's magnetism on the electric circuit.
Weber, which was found capable of explaining all the phenomena investigated by Ampere as well as the induction currents of Faraday.
When Lyons was taken by the army of the Convention in 1793, the father of Ampere, who, holding the office of juge de paix, had stood out resolutely against the previous revolutionary excesses, was at once thrown into prison, and soon after perished on the scaffold.
From about 1796 Ampere gave private lessons at Lyons in mathematics, chemistry and languages; and in 1801 he removed to Bourg, as professor of physics and chemistry, leaving his ailing wife and infant son at Lyons.
It is on the service that he rendered to science in establishing the relations between electricity and magnetism, and in developing the science of electromagnetism, or, as he called it, electrodynamics, that Ampere's fame mainly rests.
The great amiability and childlike simplicity of Ampere's character are well brought out in his Journal et correspondence (Paris, 1872).
An alternating current of one ampere is defined to be one which produces the same heat in a second in a wire as the unit continuous current defined as above to be one ampere.Advertisement
The instrument therefore does not begin to read from zero current, but from some higher limit which, generally speaking, is about one-tenth of the maximum, so that an ammeter reading up to io amperes will not give much visible indication below i ampere.
The great novelty in the ampere balances of Lord Kelvin was a joint or electric coupling, which is at once exceedingly flexible and yet capable of being constructed to carry with safety any desired current.
The mean result of the best determinations shows that when a current of one ampere is passed for one second, a mass of silver is deposited equal to o ooi i 18 gramme.
Ferromagnetism was explained by Ampere on the hypothesis that the magnetization of the molecule is due to an electric current constantly circulating within it.
The theory now most in favour is merely a development of Ampere's hypothesis, and applies not only to ferromagnetics, but to paramagnetics as well.Advertisement
Ampere's experimental and theoretical investigation of the mutual action of electric currents, and of the equivalence of a closed circuit to a polar magnet, the latter suggesting his celebrated hypothesis that molecular currents were the cause of magnetism.
The shunted voltameter was then inserted in series with the electric supply mains leading to the house or building taking electric energy, and the current which passed dissolved the zinc from one plate and deposited it upon the other, so that after a certain interval of time had elapsed the altered weight of the plates enabled the quantity of electricity to be determined from the known fact that an electric current of one ampere, flowing for one hour, removes 1.2533 grammes of zinc from a solution of sulphate of zinc. Hence the quantity in amperehours passing through the electrolytic cell being known and the fraction of the whole quantity taken by the cell being known, the quantity supplied to the house was determined.
With a supply pressure of 200 volts a 5 c.p. carbon filament lamp takes only 0.1 ampere; hence unless a meter will begin to register with 1 1 - 6 - ampere it will fail to record the current consumed by a single small incandescent lamp. In a large supply system such failure would mean a serious loss of revenue.
If the wire has a resistance of 300 ohms and is connected to two points differing in potential by 100 volts, the instrument passes a current of one-third of an ampere and takes up 33 watts in power.
Ampere's investigations had led electricians to see that the force acting upon a magnetic pole due to a current in a neighbouring conductor was such as to tend to cause the pole to travel round the conductor.Advertisement
In 1846 Weber proceeded with improved apparatus to test Ampere's laws of electrodynamics.
Neumann in 1845 did for electromagnetic induction what Ampere did for electrodynamics, basing his researches upon the experimental laws of Lenz.
Turning to practical applications of electricity, we may note that electric telegraphy took its rise in 1820, beginning with a suggestion of Ampere immediately after Oersted's discovery.
See Diderot's Prospectus (Muvres, iii.) and d'Alembert's Discours (Ouvres,i.) The scheme should be compared with later attempts of the same nature by Ampere, Cournot, Comte and Herbert Spencer.
Electric current ampere A The current which produces a specified force between two parallel wires which are 1 meter apart in a vacuum.Advertisement
The development of the atomic theory and its concomitants - the laws of chemical combination and the notion of atoms and equivalents - at the hands of Dalton and Berzelius, the extension to the modern theory of the atom and molecule, and to atomic and molecular weights by Avogadro, Ampere, Dumas, Laurent, Gerhardt, Cannizzaro and others, have been noted.
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.
See Ampere, Ballanche (Paris, 1848); Ste Beuve, Portraits contemporains, vol.
If, instead of the ampere, we take the C.G.S.
Additional evidence as to the structure of the molecule was discussed by Avogadro in 1811, and by Ampere in 1814.
Kelvin ampere balances are made in two types - (i) a variable weight type suitable for obtaining the ampere value of any current within their range; and (2) a fixed weight type intended to indicate when a current which can be varied at pleasure has a certain fixed value.
Thus the centi-ampere balance ranges from i to ioo centi-amperes, the deci-ampere balance from i to ioo deci-amperes, the ampere balance from i to ioo amperes, the deka-ampere balance from i to ioo amperes, the hecto-ampere balance from 6 to 600 amperes, and the kilo-ampere balance from ioo to 2500 amperes.
So accurate and convenient is this determination that it is now used conversely as a practical definition of the ampere, which (defined theoretically in terms of magnetic force) is defined practically as the current which in one second deposits i '18 milligramme of silver.
An instrument of the latter type of considerable accuracy was designed by Lord Kelvin for the British Board of Trade Electrical Laboratory, and it is there used as the principal standard ampere balance.
In the use of ammeters in which the control is the gravity of a weight, such as the Kelvin ampere balances and other instruments, it should be noted that the scale reading or indication of the instrument will vary with the latitude and with the height of the instrument above the mean sea-level.
A continuous electric current of one ampere is defined to be one which deposits electrolytically 0.001118 of a gramme of silver per second from a neutral solution of silver nitrate.'
Very convenient and accurate instruments based on the above principles have been devised by Lord Kelvin, and a large variety of these ampere balances, as they are called, suitable for measuring currents from a fraction of an ampere up to many thousands of amperes, have been constructed by that illustrious inventor.
By a series of well-chosen experiments Ampere established the laws of this mutual action, and not only explained observed facts by a brilliant train of mathematical analysis, but predicted others subsequently experimentally realized.
Faraday and others then discovered, as already mentioned, means to make the conductor conveying the current rotate round a magnetic pole, and Ampere showed that a magnet could be made to rotate on its own axis when a current was passed through it.
The young Ampere, however, soon resumed his Latin lessons, to enable him to master the works of Euler and Bernouilli.
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.
Ampere, Wollaston and others, the realization of the continuous rotation of the wire and the magnet round each other was a scientific puzzle requiring no mean ingenuity for its original solution.
Nothing is more remarkable in the history of discovery than the manner in which Ampere seized upon the right clue which enabled him to disentangle the complicated phenomena of electrodynamics and to deduce them all as a consequence of one simple fundamental law, which occupies in electrodynamics the position of the Newtonian law of gravitation in physical astronomy.
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.