How is magnetic induction flux measured? Basic formulas. Magnetic flux and frame - consider an example

Among the many definitions and concepts associated with the magnetic field, special mention should be made of magnetic flux, which has a certain directionality. This property is widely used in electronics and electrical engineering, in the design of instruments and devices, as well as in the calculation of various circuits.

Concept of magnetic flux

First of all, it is necessary to establish exactly what is called magnetic flux. This value should be considered in combination with a uniform magnetic field. It is homogeneous at every point in the designated space. A certain surface having a certain area, designated by the symbol S, is affected by the magnetic field. The field lines act on this surface and intersect it.

Thus, the magnetic flux Ф, crossing a surface with area S, consists of a certain number of lines coinciding with the vector B and passing through this surface.

This parameter can be found and displayed in the form of the formula Ф = BS cos α, in which α is the angle between the normal direction to the surface S and the magnetic induction vector B. Based on this formula, it is possible to determine the magnetic flux with a maximum value at which cos α = 1 , and the position of vector B will become parallel to the normal perpendicular to the surface S. And, conversely, the magnetic flux will be minimal if vector B is located perpendicular to the normal.

In this version, vector lines simply slide along the plane and do not intersect it. That is, the flux is taken into account only along the lines of the magnetic induction vector intersecting a specific surface.

To find this value, weber or volt-seconds are used (1 Wb = 1 V x 1 s). This parameter can be measured in other units. The smaller value is the maxwell, which is 1 Wb = 10 8 μs or 1 μs = 10 -8 Wb.

Magnetic field energy and magnetic flux

If an electric current is passed through a conductor, a magnetic field with energy is formed around it. Its origin is associated with the electrical energy of the current source, which is partially consumed to overcome the self-inductive emf that occurs in the circuit. This is the so-called self-energy of the current, due to which it is formed. That is, the field and current energies will be equal to each other.

The value of the current's own energy is expressed by the formula W = (L x I 2)/2. This definition is considered equal to the work done by a current source that overcomes inductance, that is, the self-inductive emf and creates a current in an electrical circuit. When the current stops operating, the energy of the magnetic field does not disappear without a trace, but is released, for example, in the form of an arc or spark.

The magnetic flux arising in the field is also known as magnetic induction flux with a positive or negative value, the direction of which is conventionally designated by a vector. As a rule, this flow passes through a circuit through which electric current flows. With a positive direction of the normal relative to the contour, the direction of current movement is a value determined in accordance with. In this case, the magnetic flux created by a circuit with an electric current and passing through this circuit will always have a value greater than zero. Practical measurements also indicate this.

Magnetic flux is usually measured in units established by the international SI system. This is the already well-known Weber, which represents the amount of flow passing through a plane with an area of ​​1 m2. This surface is placed perpendicular to the magnetic field lines with a uniform structure.

This concept is well described by Gauss's theorem. It reflects the absence of magnetic charges, so induction lines always appear closed or going to infinity without beginning or end. That is, the magnetic flux passing through any type of closed surface is always zero.

The flow of the magnetic induction vector B through any surface. The magnetic flux through a small area dS, within which the vector B is unchanged, is equal to dФ = ВndS, where Bn is the projection of the vector onto the normal to the area dS. Magnetic flux F through the final... ... Big Encyclopedic Dictionary

MAGNETIC FLUX- (magnetic induction flux), flux F of the magnetic vector. induction B through k.l. surface. M. p. dФ through a small area dS, within the limits of which the vector B can be considered unchanged, is expressed by the product of the area size and the projection Bn of the vector onto ... ... Physical encyclopedia

magnetic flux- A scalar quantity equal to the flux of magnetic induction. [GOST R 52002 2003] magnetic flux The flux of magnetic induction through a surface perpendicular to the magnetic field, defined as the product of the magnetic induction at a given point by the area... ... Technical Translator's Guide

MAGNETIC FLUX- (symbol F), a measure of the strength and extent of the MAGNETIC FIELD. The flux through area A at right angles to the same magnetic field is Ф = mHA, where m is the magnetic PERMEABILITY of the medium, and H is the intensity of the magnetic field. Magnetic flux density is the flux... ... Scientific and technical encyclopedic dictionary

MAGNETIC FLUX- flux Ф of the magnetic induction vector (see (5)) B through the surface S normal to the vector B in a uniform magnetic field. SI unit of magnetic flux (cm) ... Big Polytechnic Encyclopedia

MAGNETIC FLUX- a value characterizing the magnetic effect on a given surface. The magnetic field is measured by the number of magnetic lines of force passing through a given surface. Technical railway dictionary. M.: State transport... ... Technical railway dictionary

Magnetic flux- a scalar quantity equal to the flux of magnetic induction... Source: ELECTRICAL ENGINEERING. TERMS AND DEFINITIONS OF BASIC CONCEPTS. GOST R 52002 2003 (approved by Resolution of the State Standard of the Russian Federation dated 01/09/2003 N 3 art.) ... Official terminology

magnetic flux- flux of magnetic induction vector B through any surface. The magnetic flux through a small area dS, within which the vector B is unchanged, is equal to dФ = BndS, where Bn is the projection of the vector onto the normal to the area dS. Magnetic flux F through the final... ... encyclopedic Dictionary

magnetic flux- , the flux of magnetic induction is the flux of the magnetic induction vector through any surface. For a closed surface, the total magnetic flux is zero, which reflects the solenoidal nature of the magnetic field, i.e. the absence in nature... Encyclopedic Dictionary of Metallurgy

Magnetic flux- 12. Magnetic flux Magnetic induction flux Source: GOST 19880 74: Electrical engineering. Basic concepts. Terms and definitions original document 12 magnetic on ... Dictionary-reference book of terms of normative and technical documentation

Books

  • , Mitkevich V. F. Category: Mathematics Publisher: YOYO Media, Manufacturer: Yoyo Media, Buy for 2591 UAH (Ukraine only)
  • Magnetic flux and its transformation, Mitkevich V.F., This book contains a lot that is not always paid due attention when it comes to magnetic flux, and that has not yet been stated clearly enough or has not been... Category: Mathematics and science Series: Publisher:

Common industrial ones used to account for products and raw materials include commodity, automobile, carriage, trolley, etc. Technological ones are used for weighing products during production in technologically continuous and periodic processes. Laboratory tests are used to determine the moisture content of materials and semi-finished products, conduct physical and chemical analysis of raw materials and other purposes. There are technical, exemplary, analytical and microanalytical.

They can be divided into a number of types depending on the physical phenomena on which the principle of their operation is based. The most common devices are magnetoelectric, electromagnetic, electrodynamic, ferrodynamic and induction systems.

The diagram of the magnetoelectric system device is shown in Fig. 1.

The fixed part consists of a magnet 6 and a magnetic circuit 4 with pole pieces 11 and 15, between which a strictly centered steel cylinder 13 is installed. In the gap between the cylinder and the pole pieces, where a uniform radially directed direction is concentrated, a frame 12 made of thin insulated copper wire is placed.

The frame is mounted on two axes with cores 10 and 14, resting on thrust bearings 1 and 8. Counteracting springs 9 and 17 serve as current leads connecting the frame winding to the electrical circuit and input terminals of the device. On the axis 4 there is a pointer 3 with balance weights 16 and an opposing spring 17 connected to the corrector lever 2.

01.04.2019

1. The principle of active radar.
2. Pulse radar. Principle of operation.
3. Basic time relationships of pulse radar operation.
4.Types of radar orientation.
5. Formation of a sweep on the PPI radar.
6. The principle of operation of the induction lag.
7.Types of absolute lags. Hydroacoustic Doppler log.
8.Flight data recorder. Description of work.
9. Purpose and operating principle of AIS.
10.Transmitted and received AIS information.
11.Organization of radio communications in AIS.
12.Composition of shipboard AIS equipment.
13. Structural diagram of the ship's AIS.
14. Operating principle of SNS GPS.
15.The essence of differential GPS mode.
16. Sources of errors in GNSS.
17. Block diagram of a GPS receiver.
18. Concept of ECDIS.
19.Classification of ENC.
20.Purpose and properties of the gyroscope.
21. The principle of operation of the gyrocompass.
22. The principle of operation of a magnetic compass.

Connecting cables— a technological process for obtaining an electrical connection between two sections of cable with the restoration of all protective and insulating sheaths of the cable and screen braids at the junction.

Before connecting the cables, the insulation resistance is measured. For unshielded cables, for ease of measurement, one terminal of the megohmmeter is connected in turn to each core, and the second - to the remaining cores connected to each other. The insulation resistance of each shielded core is measured when connecting the leads to the core and its screen. , obtained as a result of measurements, must be no less than the standardized value established for a given cable brand.

Having measured the insulation resistance, they move on to establishing either the numbering of the cores, or the directions of laying, which are indicated by arrows on temporarily attached tags (Fig. 1).

Having completed the preparatory work, you can begin cutting the cables. The geometry of the cutting of the cable ends is modified in order to ensure the convenience of restoring the insulation of the cores and sheath, and for multi-core cables, also to obtain acceptable dimensions of the cable connection.

METHODOLOGICAL GUIDE TO PRACTICAL WORK: “OPERATION OF SPP COOLING SYSTEMS”

BY DISCIPLINE: " OPERATION OF POWER INSTALLATIONS AND SAFE WATCH KEEPING IN THE ENGINE ROOM»

COOLING SYSTEM OPERATION

Purpose of the cooling system:

  • heat removal from the main engine;
  • heat removal from auxiliary equipment;
  • heat supply to the OS and other equipment (GD before start-up, VDG maintenance in “hot” reserve, etc.);
  • intake and filtration of sea water;
  • blowing out Kingston boxes in summer from clogging with jellyfish, algae, dirt, in winter - from ice;
  • ensuring the operation of ice chests, etc.
Structurally, the cooling system is divided into fresh water and intake water cooling systems. ADF cooling systems are performed autonomously.

Ampere's law is used to establish the unit of current, the ampere.

Ampere - the strength of a current of constant magnitude, which, passing through two parallel straight conductors of infinite length and negligibly small cross-section, located at a distance of one meter, one from the other in a vacuum, causes a force of .

, (2.4.1)

Here ; ; ;

Let us determine from here the dimension and magnitude in SI.

, hence

, or .

From the Biot-Savart-Laplace law, for a straight conductor with current , Same you can find the dimension of the magnetic field induction:

Tesla is the SI unit of induction. .

Gauss– unit of measurement in the Gaussian system of units (GHS).

1 T is equal to the magnetic induction of a uniform magnetic field, in which a flat circuit with a current having a magnetic moment,torque is applied.

Tesla Nikola(1856–1943) – Serbian scientist in the field of electrical and radio engineering. He had a huge number of inventions. He invented the electric meter, frequency meter, etc. He developed a number of designs for multiphase generators, electric motors and transformers. He designed a number of radio-controlled self-propelled mechanisms. Studied the physiological effects of high frequency currents. In 1899 he built a 200 kW radio station in Colorado and a 57.6 m high radio antenna in Long Island (Wardenclyffe Tower). Together with Einstein and Openheimer, in 1943 he participated in a secret project to achieve the invisibility of American ships (Philadelphia experiment). Contemporaries spoke of Tesla as a mystic, clairvoyant, prophet, capable of looking into the intelligent cosmos and the world of the dead. He believed that with the help of an electromagnetic field one could move in space and control time.

Other definition: 1 T equal to magnetic induction, at which the magnetic flux through the area 1 m 2, perpendicular to the field direction,equals 1 Wb .

The unit of measurement of magnetic flux Wb, got its name in honor of the German physicist Wilhelm Weber (1804–1891), a professor at universities in Halle, Göttingen, and Leipzig.

As we already said, magnetic flux Ф through the surface S is one of the characteristics of the magnetic field(Fig. 2.5):

SI unit of magnetic flux:

. , and since , then .

Here Maxwell(Mks) is a unit of measurement of magnetic flux in the CGS named after the famous English scientist James Maxwell (1831–1879), creator of the theory of the electromagnetic field.

Magnetic field strength N measured in .

, .

Let us summarize the main characteristics of the magnetic field in one table.

Table 2.1

Name


Electric dipole moment
Electric charge
Electrical induction
Electric field
Electrostatic potential See also: Portal:Physics

Magnetic flux- physical quantity equal to the product of the magnitude of the magnetic induction vector \vec B by area S and cosine of angle α between vectors \vec B and normal \mathbf(n). Flow \Phi_B as the integral of the magnetic induction vector \vec B through end surface S is determined through the surface integral:

{{{1}}}

In this case, the vector element d S surface area S defined as

{{{1}}}

Magnetic flux quantization

Values ​​of magnetic flux Φ passing through

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Excerpt characterizing Magnetic Flux

“C"est bien, mais ne demenagez pas de chez le prince Vasile. Il est bon d"avoir un ami comme le prince,” she said, smiling at Prince Vasily. - J"en sais quelque chose. N"est ce pas? [That's good, but don't move away from Prince Vasily. It's good to have such a friend. I know something about this. Isn't that right?] And you are still so young. You need advice. Don't be angry with me for taking advantage of old women's rights. “She fell silent, as women always remain silent, expecting something after they say about their years. – If you get married, then it’s a different matter. – And she combined them into one look. Pierre did not look at Helen, and she did not look at him. But she was still terribly close to him. He mumbled something and blushed.
Returning home, Pierre could not fall asleep for a long time, thinking about what happened to him. What happened to him? Nothing. He just realized that the woman he knew as a child, about whom he absentmindedly said: “Yes, she’s good,” when they told him that Helen was beautiful, he realized that this woman could belong to him.
“But she’s stupid, I said myself that she’s stupid,” he thought. “There is something nasty in the feeling that she aroused in me, something forbidden.” They told me that her brother Anatole was in love with her, and she was in love with him, that there was a whole story, and that Anatole was sent away from this. Her brother is Hippolytus... Her father is Prince Vasily... This is not good,” he thought; and at the same time as he reasoned like this (these reasonings still remained unfinished), he found himself smiling and realized that another series of reasoning was emerging from behind the first, that at the same time he was thinking about her insignificance and dreaming about how she will be his wife, how she can love him, how she can be completely different, and how everything that he thought and heard about her may not be true. And again he saw her not as some daughter of Prince Vasily, but saw her whole body, only covered with a gray dress. “But no, why didn’t this thought occur to me before?” And again he told himself that this was impossible; that something disgusting, unnatural, as it seemed to him, would be dishonest in this marriage. He remembered her previous words, looks, and the words and looks of those who saw them together. He remembered the words and looks of Anna Pavlovna when she told him about the house, he remembered thousands of such hints from Prince Vasily and others, and horror came over him, whether he had already tied himself in some way in carrying out such a task, which was obviously not good and which he should not do. But at the same time, as he expressed this decision to himself, from the other side of his soul her image emerged with all its feminine beauty.

In November 1805, Prince Vasily was supposed to go to an audit in four provinces. He arranged this appointment for himself in order to visit his ruined estates at the same time, and taking with him (at the location of his regiment) his son Anatoly, he and he would go to Prince Nikolai Andreevich Bolkonsky in order to marry his son to the daughter of this rich man old man. But before leaving and these new affairs, Prince Vasily needed to resolve matters with Pierre, who, however, had recently been spending whole days at home, that is, with Prince Vasily, with whom he lived, he was funny, excited and stupid (as he should to be in love) in the presence of Helen, but still did not propose.