Permanent-magnet Sentence Examples
A small permanent magnet is always liable to become demagnetized, or have its polarity reversed by the action of lightning.
This liability is overcome by making such movable parts as require to be magnetic of soft iron, and magnetizing them by the inducing action of a strong permanent magnet.
A much better form of electromagnetic ammeter can be constructed on a principle now extensively employed, which consists in pivoting in the strong field of a permanent magnet a small coil through which a part of the current to be measured is sent.
It is essential that the permanent magnet should be subjected to a process of ageing so that its field may not be liable to change subsequently with time.
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.Advertisement
Even a permanent magnet is susceptible of induction, its polarity becoming thereby strengthened, weakened, or possibly reversed.
It is suggested that a permanent magnet might conveniently be " aged " (or brought into a constant condition) by dipping it several times into liquid air.
In its improved form this meter consists of a single horseshoe permanent magnet formed of tungsten-steel having a strong and constant field.
The driving force is balanced against a retarding force produced by the rotation of a copper disk fixed on the armature shaft, which rotates between the poles of a permanent magnet.
By the use of a permanent magnet instead of a shunt coil as the bob of one pendulum, the meter can be made up as an ampere-hour meter.Advertisement
In 1821 Michael Faraday (1791-1867), who was destined later on to do so much for the science of electricity, discovered electromagnetic rotation, having succeeded in causing a wire conveying a voltaic current to rotate continuously round the pole of a permanent magnet.
Just inside the bore of the permanent magnet is a resistive magnet, made from copper conductor in a saddle configuration.
The display uses a permanent magnet that is perforated to provide an aperture for each pixel.
The sensors contain a permanent magnet and wire coil.
The heart of a normal eddy current separator is a powerful permanent magnet that revolves at very high speed.Advertisement
It was also found that comparatively small magnets were sufficient, and that there was no particular virtue in the closed circuit and electromagnet, but that a small permanent magnet having one pole in contact with FIG.
Along with this, the turbine is also equipped with a couple of permanent magnet alternators which are connected to the blades.