Word Finder - magnets

definition

A piece of material that attracts some metals by magnetism.

definition

(preceded by a noun) A person or thing that attracts what is denoted by the preceding noun.

example

He always had a girl on his arm – he's a bit of a babe magnet.

He invented magnets that could withstand the effects of percussion and ordinary temperature variations.

The axis of the magnet is horizontal and at the same level as the mirror magnet, while when the central division of the scale B appears to coincide with the vertical cross-wire of the telescope the axes of the two magnets are at right angles.

It consists of a disk of aluminium, the axis of which is geared to a counting mechanism and which runs between the poles of permanent magnets that create eddy currents in it and therefore exert a retarding force.

According to this theory the molecules of any magnetizable substance are little permanent magnets the axes of which are, under ordinary conditions, disposed in all possible directions indifferently.

The magnets hitherto considered have been assumed to have each two poles, the one north and the other south.

A magnet may be regarded as consisting of an infinite number of elementary magnets, each having a pair of poles and a definite magnetic moment.

If two magnets having moments M, M' are arranged at right angles to each other upon a horizontal support which is free to rotate, their resultant R will set itself in the magnetic meridian.

At shorter distances the magnetism induced in the weaker magnet will be stronger than its permanent magnetism, and there will be attraction; two magnets with their like poles in actual contact will always cling together unless the like poles are of exactly equal strength.

The effect of the field upon the speed of the revolving electrons, and therefore upon the moments of the equivalent magnets, is necessarily a very small one.

Since the poles of different magnets differ in strength, it is important to agree upon a definite unit or standard of reference in terms of which the strength of a pole may be numerically specified.

One of the fragments may again be broken, and again two bipolar magnets will be produced; and the operation may be repeated, at least in imagination, till we arrive at molecular magnitudes and can go no farther.

The distribution of magnetism and the position of the poles in magnets of other shapes, such as cylindrical or rectangular bars, cannot be specified by any general statement, though approximate determinations may be obtained experimentally in individual cases.'

A very pure form of iron, which from the method of its manufacture is called " steel," is now extensively used for the construction of dynamo magnets; this metal sometimes contains not more than 0.3% of foreign substances, including carbon, and is magnetically superior to the best commercial wrought iron.

Ordinarily a substance composed of asymmetrical molecules is paramagnetic, but if the elementary magnets are so conditioned by their strength and concentration that mutual action between them is possible, then the substance is ferromagnetic. In all cases however it is the diamagnetic condition that is initially set up - even iron is diamagnetic - though the diamagnetism may be completely masked by the superposed paramagnetic or ferromagnetic condition.

The term " electricity " is applied to denote the physical agency which exhibits itself by effects of attraction and repulsion when particular substances are rubbed or heated, also in certain chemical and physiological actions and in connexion with moving magnets and metallic circuits.

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.

Electric magnets of great power were soon constructed in this manner by Sturgeon, Joule, Henry, Faraday and Brewster.

All the space round magnets, currents and electric charges was therefore to Faraday the seat of corresponding lines of magnetic or electric force.

Holmes had made a magneto machine with multiple permanent magnets which was installed in 1862 in Dungeness lighthouse.

This work, which embodied the results of many years' research, was distinguished by its strict adherence to the scientific method of investigation by experiment, and by the originality of its matter, containing, as it does, an account of the author's experiments on magnets and magnetical bodies and on electrical attractions, and also his great conception that the earth is nothing but a large magnet, and that it is this which explains, not only the direction of the magnetic needle north and south, but also the variation and dipping or inclination of the needle.

The boots were working like sticky glue or magnets.

The needle (in the modern pattern) is of soft iron, and is kept magnetized in ductively by the action of two permanent steel magnets.

Steel is much more retentive of magnetism than any ordinary iron, and some form of steel is now always used for making artificial magnets.

The process of magnetization consists in turning round the molecules by the application of magnetic force, so that their north poles may all point more or less approximately in the direction of the force; thus the body as a whole becomes a magnet which is merely the resultant of an immense number of molecular magnets.

A well-known example of hysteresis is presented by the case of permanent magnets.

A metal which has great retentiveness may at the same time have small coercive force, and it is the latter quality which is of chief importance in permanent magnets.

The distinguishing feature of the first is the steepness of its outlines; this indicates that the induction increases rapidly in relation to the magnetic force, and hence the metal is well suited for the construction of dynamo magnets.

Eschenhagen 2 first designed a set of magnetographs in which this idea of small moment of inertia was carried to its useful limit, the magnets only weighing 1 .

In the Eschenhagen pattern instrument, in which a single quartz fibre is used for the suspension, two magnets are placed in the vicinity of the suspended magnet and are so arranged that their field partly neutralizes the earth's field; thus the torsion required to hold the magnet with its axis perpendicular to the earth's field is reduced, and the arrangement permits of the sensitiveness being altered by changing the position of the deflecting magnets.

In the Eschenhagen form of vertical force balance two deflecting magnets are used to partly neutralize the vertical component, so that the centre of gravity is almost exactly over the support.

Wilde introduced the use of electromagnets for the field magnets.

In 1750 he published at Cambridge a work of some eighty pages entitled A Treatise of Artificial Magnets, in which is shown an easy and expeditious method of making them superior to the best natural ones.

Henry's "quantity" magnets acquired considerable celebrity at the time, from their unprecedented attractive power - one (August 1830) lifting 750 lb, another (March 1831) 2300, and a third (1834) 3500.

In 1835 he combined the short circuit of his monster magnet (of 1834) with the small "intensity" magnet of an experimental telegraph wire, thereby establishing the fact that very powerful mechanical effects could be produced at a great distance by the agency of a very feeble magnet used as a circuit maker and breaker, or as a "trigger" - the precursor of later forms of relay and receiving magnets.

At the age of nineteen, he was articled for five years as clerk to the master of a school in Spital Square, London, with whom at the end of that time he entered into partnership. In 1750 he read a paper before the Royal Society on a method of making artificial magnets, which procured him election as a fellow of the society and the award of the Copley medal.

The magnets are either sintered or directionally cast, and then annealed in a magnetic field.

Ball and socket armatures have metal feet, which can be used on thin set floors with magnets underneath.

Perhaps it's down to the magnets used blah blah blah.

First, it is essential to use the strongest magnets available, preferably neodymium iron boron.

Powerful magnets aimed at the motor cortex have been shown to induce muscles to twitch.

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However, traditional magnets made of iron were too heavy, so this led to the development of extremely high-powered magnets that were lightweight.

To further boost the strength of my magnets I started to wear magnetic insoles.

The repulsive force between like poles of magnets can be used for magnetic levitation which engineers are trying to exploit in modern train systems.

Both bending magnets in the cell cannot be used due to space restrictions on the experimental floor.

The rotor, incorporating permanent magnets, runs in a bore with a gap of just 1mm.

Coral reefs are irresistible magnets to many varieties of fish and support a huge amount of marine life.

Another thing, forget about ceramic magnets on your speakers, to be Fifties you'll need the good ole blue cobalt stuff.

However, due to their high cost they did not gain widespread use and the rare-earth magnets superseded them.

The powerful curved ceramic ferrite magnets contained in Aquamag produce a super field of high magnetic flux.