PHY_10_60_V1_P_Artificial magnets. Solenoid

Artificial magnets. Solenoid

10.4.1.4 – to make an artificial magnet empirically and explain the scopes of
its application;

10.4.1.5 – to explain the factors having an effect on a magnetic field of a
solenoid.

Natural magnets

A natural magnet is a magnet found in nature. All natural magnets are permanent magnets, which means that they will never lose their magnetic force. Natural magnets can be found in sandy sediments in different parts of the world. The strongest natural magnet is magnetite (magnetic iron ore). This mineral is black in color and very shiny when polished. In fact, this magnet was used in the very first compasses ever made. Since natural magnets are permanent magnets, if the magnet is allowed to rotate freely, it will be oriented in the Earth’s magnetic field.

Causes of Magnetism

Whether a material is a magnet or not depends on the atoms of the material. In materials such as iron, nickel, and cobalt, the groups of atoms are in tiny regions called domains. The location of the domains in the object determines whether the object is a magnet. When domains are moved, the magnet is demagnetized or loses its magnetic properties.

There are other minerals that are natural magnets, but they have weak magnetic properties. Some of them are pyrrhotite, ferrite and columbite.

pyrrhotite

ferrite

columbite

Artificial magnets

Artificial magnets are man-made magnets. It is these magnets that are on the door of your refrigerator, and they have magnetic power, just like those tiny permanent magnets that you can buy at the toy store.

Poles of magnets

Magnets are strongest on both sides, called the "North Pole" and the "South Pole"

Magnets interaction

Two types of magnets: permanent and non-permanent

Inconstant magnet
(electromagnet)

Permanent artificial magnet

Non-permanent: when charged particles move in space, they create a magnetic field (electromagnets) - artificial magnets
Permanent: Electrons have their own magnetic field, which can develop in a particular substance, creating a magnetic field (spin) - natural and artificial magnets

Permanent natural  magnet

A permanent artificial magnet is an object made of a material that is magnetized and creates its own permanent magnetic field. Example: a magnet used to store notes on a refrigerator door (permanent artificial magnet).

Creating an artificial magnet

A magnet can be created by magnetizing a piece of iron or steel (permanent magnet) or using an electric current in an electromagnet (non-permanent magnet).

Artificial magnets

Artificial magnets are made by: Magnetization of iron, nickel, cobalt and alloys of the above metals Electromagnet assembly

Use of magnets

Transformers
Hard and floppy disks for phones and computers
VCRs and cassettes
Credit cards
Speakers
Motors (both AC and DC) Speed ​​sensors Solenoids for relays, valves, etc.
Magnetos (aircraft with a piston engine)

Your radio speakers and televisions have permanent magnets surrounding the electromagnet, which is attached to the loudspeaker membrane.

By changing the electric current through the wires around the electromagnet, the diffuser (membrane) speaker moves forward and backward.
The resulting vibration of the speaker cone will create sound waves — voices and music.

Magnetic cushion trains

Magnetic + Levitation = maglev
Maglev trains “float” above a fixed steel cushion with an electromagnetic drive. Driven by current, the movement occurs without engines, without wheels and without additional energy sources. The system is environmentally friendly, energy efficient and works in all weather conditions.

http://dsc.discovery.com/videos/extreme-engineering-season-1-shorts-maglev-train.html

Main conclusions

All magnets have North and South poles.
The magnetic field lines begin at the north and end at the south pole.
The magnetic field lines do not intersect.
Magnetism exists at the atomic level.
Magnetism is the result of moving charges.
Some magnets are non-permanent, while others are permanent.
Types of magnetism: ferromagnetism, paramagnetism, diamagnetism.

Solenoids are simple electrical devices that have a huge impact on everyday life. The term itself is derived from the Greek name "salty", which illustrates the channel or pipe. The second part of the name is taken from the Greek name "eidos", which means a sketch. In fact, it is a device in the form of a pipe. A solenoid has many uses, and there are many types of solenoid designs. Each of them has its own properties that make it useful in many cases. The various designs of these devices do not change their required performance, but the mechanical energy of this device is differently distributed in different designs.

A solenoid is a coil with a winding (inductor) that creates a magnetic field as the electric current passes through it.
The magnetic field strength increases with increasing number of turns and increasing electric current.

When a direct current is applied to the solenoid, it creates a constant magnetic field that arises around the conductor with current (around the coil with current).

A feature of the solenoid magnetic field. If the solenoid had infinite length, then the coil.     
 In the solenoid, and sometimes they can be done. For example, a powerful solenoid couldn’t close manually.

Solenoid application

Solenoids drive scissors for cutting tickets and checks in cash registers, lock tongues, valves in engines, hydraulic systems, etc. One of the most famous examples is the “traction relay” of a car starter. Solenoids are widely used in the power industry, having found wide application in drives of high-voltage switches.
The solenoid is used in many different devices and devices, such as computer printers, fuel injection mechanisms used in automobiles and in various industrial systems. The main advantage of the solenoid is that when the electricity is applied, the effect of the solenoid occurs instantly.

ELECTROMAGNETS

Electromagnet consists of a solenoid with an iron core.
Electromagnets are very useful because they can be turned on and off as needed. A solenoid has a field only when it has an electric current.