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Usually the term "residual magnetism" is used in referring to the weak, leftover magnetic force remaining in field coil poles in generators. These generators can be the automotive type, but can also be any other type of generator in which a Direct Current is used in a series of field windings wrapped around field cores to produce magnetic fields around a rotating armature with the purpose of producing electricity from mechanical motion (the rotating armature).
The field winding poles/cores are made of iron, and after the generator has been run a few seconds under load, will retain a weak magnetic field even after the generator has been shut down. This is the "residual magnetism". The majority of older-design generators depend upon this weak, leftover field to restart the voltage produced in the armature, rather than the voltage regulator depending upon a battery to restart the generator field magnetism.
Residual magnetism gets weaker over time; the time depends in part on the quality of the field pole piece and and how strong the current applied to the field coils was at the time the generator was stopped.
To temporarily restore the residual magnetic field, current will need to be applied to the field circuit BRIEFLY; completely disconnecting the generator will be required. Connecting a 6 volt "lantern battery" in the proper polarity across the field winding circuits for a few seconds will establish a residual magnetic field in each field coil/windingzperiodz Proper polarity is critical: backwards polarity will create backwards residual magnetic fields, and the generator will produce backwards-polarity electricity when the armature is spun.
Wiki User
∙ 14y ago
Wiki User
∙ 14y agoto reduce residual magnetism a separate softiron should rub upon it.
Wiki User
∙ 12y agoby hitting it with a hammer or heating it.
Wiki User
∙ 11y agoHi, if you really wanna reduce magnetic fringing effect, then you have to keep + side in water for two days and then can have a test of effect streangth, it will be reduced to
50%.
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What is magnetism on Mars?
The magnetic field on Mars is only residual, it collapsed many eons ago.
What is true of any ferromagnetic materials?
It has an abnormally high magnetic permeability, it has a definite saturation point, and it has appreciable residual magnetism and hysteresis. That's why it remains magnetic even after the forcing magnetic field goes away.
How can the magnetism of a permanent magnet be weakened or removed?
Put it in a coil which has an alternating current in it. The AC current produces a magnetic field in the coil which alternates with the changing voltage. This changes the magnetism of the permanent magnet. Gradually reduce the current in the coil and the permanent magnet will end up unmagnetised.
What is the magnetism of Quartz?
The magnetism of a quartz is 3.56
Does foam affect the strength of a magnet?
Magnetism is the number of magnetic moments per unit of volume, so it is the volume of the magnet that determines magnetism. If an object has great weight and volume, the magnetism will be stronger. If an object has a great weight but lesser volume, the magnetism will be weaker.?æ
What is difference between residual magnetism and retentivity?
Residual magnetism and remanence are the same thing. The term residual magnetism is often used in engineering applications. Both terms describe the magnetization, and measure of that magnetism, left behind in a ferromagnetic material after the external magnetic field is removed.
What is residual magnetism?
Residual magnetism is a property in which certain amount of excitation remains back in the conductor even after the removal of the magnets.
Can a shunt motor be started without residual magnetism?
Yes. The field is provided by the shunt windings, which are connected in parallel with the supply. You may be confusing a motor with a generator, as you cannot start a shunt generatorwithout residual magnetism.
The flux density that remains when the magnetizing force is removed is called?
residual magnetism
What is residual magnetisim?
It depends on the context in which you are referring to it, but basically Residual Magnetism is that magnetism remaining in the core of an electromagnet after the coil current is removed. In the widest use of the term, it could be used to refer to that magnetism left in a magnetically susceptible substance when it cools past its Curie point, (paleomagnetism is an example of this).
How could heating a bar magnet reduce its magnetism?
Heating a bar magnet could reduce its magnetism because the heat, by raising the energy level in the metal, disorients the atoms, which disrupts the magnetism.
How initially voltage build up in an alternator by residual magnetism?
The residual flux will help the phenomenon of changing flux. So that emf generation takes place.
What is magnetism on Mars?
The magnetic field on Mars is only residual, it collapsed many eons ago.
If a selfexcited generator has lost all of its residual magnetism can it build up an output voltage?
yes
For a 3 phase alternator why there is an AC voltage generated in the absence DC excitation?
due to residual magnetism
Is a36 steel magnetic?
A36 is paramagnetic. It is fairly good conductor of magnetic field, and it will be atracted to magnets strongly. As far as residual magnetism (can it be magnetized) I don't know for sure. I know you can not make usefully strong magnets out of A36 material, but it may have some residual magnetism.
What is the best treatment to reduce residual fibrosis?
acetylcysteine
