How do an electromagnet and a bar magnet differ in strength , polarity and stability ?
Answers
Answer:
- This causes a magnetic field to form around the wire. ... All the fields of each loop of the coil line up so that the effect is that of a natural bar magnet. One end of the coil is a north pole and the other end is a south pole. The iron core reinforces the field of the wire, making the electromagnet stronger.
- Both bar magnets and electromagnets are common types of magnets that can attract or repel things. The key difference between bar magnet and electromagnet is that the bar magnet has a permanent magnetic field whereas the electromagnet has a temporary magnetic field
Answer:
An electron with a spin: A microscopic magnet
Electron spins
In permanent magnets, the B fields are also created through currents.
But these currents are not macroscopic currents, in which charged particles flow in one direction.
They are microscopic electric currents, which, in the case of ferromagnetism, are created through certain electrons rotating around themselves in the material (electron spins).
Electron spin can be viewed as a microscopic small circulating current.
Strengths of permanent and electromagnets
The strength of a magnetic field of an electromagnet depends on the core material, the number of solenoid windings and the intensity of the current.
With a high enough amperage, the electromagnet can develop a significantly stronger magnetic field than a permanent magnet.
The strength of the electromagnet factors
The strength of the electromagnet factors
electromagnet
Left: A permanent magnet with field lines
Right: An electromagnet with the power source (left), solenoid (orange) and soft-iron core (middle)
Soft-iron core (grey) with the coil (orange)
Soft-iron core
When it comes to electromagnets, usually a soft-iron core is placed in the coil, which considerably strengthens its magnetic field, because the magnetic field of the coil magnetizes the soft-iron core and, thereby, creates an additional magnet.
The soft-iron core loses its magnetization after the current is turned off.
This is desirable in order to be able to turn the magnet on and off.
Magnetically soft and hard iron
The term magnetically "soft" is based on the fact that mechanically soft iron loses its magnetization, while the mechanically hard iron (steel) that is carbon-enriched keeps part of its magnetization.
This is called remanence.
The Latin word "remanence" means "to remain".
Material with high remanence is referred to as "magnetically hard".
Solenoids with a current flow magnetize also permanent magnets, like our super magnets, which are all made of magnetically hard material.
large rare earth neodymium n52 bar block
Electromagnets
A wire with an electric current (charged electrons) produces a magnetic field in its surroundings.
The strength of the magnetic field depends on the intensity of the current and the shape of the wire.
Each wire with a current flow is practically an electromagnet.
The orange arrow indicates the technical direction of the current.
Historically, it is the opposite of the direction of the electrons.
If you bend the wire with the current flow into a circle, it creates a magnetic field with poles.
Therefore, a circulating current creates a magnet with a north and south pole.
In common magnets, the wire is often wound into a multi-layered coil, which is also called a solenoid.
A wire coil with north and south pole
Bar Magnets and Electromagnets
An electromagnet works on the principle that an electric current allows electrons to flow in a circuit.
Bar magnet is a permanent magnet which is always magnetized; Electromagnet is a conductor
Electromagnet Science
Build an Electromagnet
If you have ever played with a really powerful magnet, you have probably noticed one problem.
You have to be pretty strong to separate the magnets again! Today, we have many uses for powerful magnets, but they wouldn’t be any good to us if we were not able to make them release the objects that they attract.
In 1820, a Danish physicist, Hans Christian Oersted, discovered that there was a relationship between electricity and magnetism.