In order to find out the trajectory of rotation magnetic field located near a direct current-carrying conductor, the gimlet (corkscrew) rule is used. In the literature, it is also known as the rule of the right hand. In the scientific community, the rule of the left hand is also distinguished.
In contact with
Application of the gimlet rule
Given rule says: if, when this device moves forward, the trajectory of the current in the conductor coincides with it, then the trajectory of rotation of the base of the device is complementary to the trajectory of the magnetic circuit.
To determine the trajectory of rotation of the magnetic circuit on the presented graphic image, you need to know several features.
Often in problems in physics, on the contrary, it is necessary to determine current path. To do this, the direction of rotation of the magnetic field circles is given. The handle of the gimlet begins to rotate in the direction indicated in the conditions. If the gimlet moves in the forward direction, then the current is directed in the direction of movement, but if it is directed in the opposite direction, then the current moves accordingly.
To determine the trajectory of the current in the case shown in the second figure, you can also use corkscrew rule. To do this, rotate the handle of the gimlet in the direction indicated on the image of the magnetic field contour. If it moves progressively, it will move away from the observer, if, on the contrary, only towards the observer.
Important! If the trajectory of the flow movement is indicated, then it is possible to determine the trajectory of rotation of the magnetic circuit line by rotating the gimlet handle.
It is denoted with dots or crosses. A dot means towards the observer, a cross means the opposite. It is easy to remember this case, using the so-called “arrow” rule, if the tip “looks”, but in the face, then the trajectory of the current movement towards the observer, but if the tail of the arrow “looks in the face”, then it moves away from the observer.
Both the gimlet rule and the right hand rule are enough easy to apply on practice. To do this, you need to position the brush of the corresponding hand in such a way that the force circuit of the magnetic field is directed to the front side, after which the thumb, taken perpendicularly, must be directed to the side of the current movement, respectively, the remaining straightened fingers will point to the trajectory of the magnetic circuit.
Distinguish exceptional cases using the right hand rule to calculate:
- Maxwell's equations;
- moment of force;
- angular velocity;
- moment of impulse;
- magnetic induction;
- current in a wire moving through a magnetic field.
left hand rule
By the rule of this hand, it is possible to calculate the direction of the force of the influence of the magnetic circuit on the charged elementary components of the atom plus and minus polarity.
It is also possible to determine the direction of the current if information is available on the trajectories of rotation of the magnetic circuit and acting on the conductor. The direction of the magnetic circuit is also determined if the trajectory of the movement of force and current is known. Well, you can find out the sign of the charge of a non-static particle.
This rule is as follows: by placing the front part of the hand of the corresponding hand so that the imaginary contour of the magnetic field is directed into it at a right angle, and fingers, with the exception of the thumb, pointing in the direction of current flow, you can determine the trajectory of the force acting on this wire with the help of perpendicular retracted thumb. The force acting on the conductor is called Marie Ampere, discovered it in 1820.
Ampere Force: Calculation Options
Before formulating given value, it is necessary to understand what the concept of "force" is in physics. It is called a quantity in physics, which is impact measure of all surrounding bodies on the object under consideration. Usually any force is denoted English letter F, from the Latin fortis, meaning strong.
Calculated elemental power Ampere according to the formula:
where, dl is part of the length of the conductor, B is the magnetic circuit, I is the current strength.
The Ampere force is also calculated by:
where, J is the direction of the current density, dv is the volume element of the conductor.
The formula for calculating the Ampere force module, according to the literature, sounds like this: this indicator directly depends on the current strength, the length of the conductor, the sine formed between this vector and the angle conductor itself, and the magnitude of the value of the magnetic circuit vector in the module. It is called the Ampere force module. The formula of this law is mathematically constructed as follows:
where, B is the induction modulus of the magnetic circuit, I is the current strength, l is the length of the conductor, α is the angle formed. The maximum value will be at their perpendicular intersection.
Indicator measured in Newton x (symbol - H) or
It is a vector quantity and depends on the vector of induction and current.
There are other formulas for calculating the Ampère force. But in practice, they are rarely needed and difficult to understand.
Current strength
- Ohm's law for the complete section of the chain and its part;
- the ratio of voltage and sum of resistances;
- the ratio of power and voltage.
The most popular is the ratio of the amount of charge passed per unit of time through a certain surface to the size of this interval. Graphically the formula looks like in the following way:
To find this indicator, you can use Ohm's law for the chain section. It reads as follows: the value of this indicator is equal to the ratio of the applied voltage to the resistance in the measured section of the circuit. The formula of this law is written as follows:
You can also determine it by applying the Ohm's law formula for a complete chain. It sounds like this: this value is the ratio of the applied voltage in the circuit and the sum internal resistance power supply and all resistance in the circuit. The formula looks like this:
Important! The application of each particular formula depends on the data available.
According to the approved MCE, the current strength is measured in amps and is designated A (in honor of the scientist who discovered it). But this is not the only way to designate this quantity. Additionally, the current strength is measured in C/s.
Studying in educational institutions given material, students quickly forget how to apply the rules of the left and right hand, and what they are for at all. Also, often they do not remember what the indicated quantities are measured in. Having become acquainted with the material discussed above, there should be no difficulty in applying the considered rules and laws in practice.
gimlet rule
Right hand rule
To indicate the direction of current, magnetic lines and others physical values in science, the rule of the left hand and the rule of the right hand (the law of a gimlet or screw) are used. These methods in practice give the most accurate results. Let's consider each of them in more detail.
Gimlet Rule
This rule in practice is quite convenient for determining such a value of the magnetic field as the direction of the intensity. It is possible to use this rule provided that a magnetic field is located in a straight line to the current-carrying conductor. With its help, it is possible to determine various physical quantities (moment of forces, momentum, magnetic induction vector) without the presence of specialized instruments.
This rule is:
- explains the peculiarity of electromagnetism;
- explains the physics of the movement of magnetic fields accompanying it.
The wording of the gimlet rule is as follows: if a gimlet with a right-hand thread is screwed along the streamline, then the direction of the magnetic field coincides with the direction of the handle of this gimlet.
The basic principle used in the screw rule is the choice of directionality for bases and vectors. Often in practice it is determined to use the right basis. The left bases are used extremely rarely, in the case when the use of the right one is inconvenient or generally inappropriate. This principle also applies to the solenoid.
solenoid is called a coil with closely tied turns. The main requirement is the length of the coil, which must be significantly larger than its diameter.
Solenoid rings resemble the field of a continuous magnet. The magnetic needle, being in free rotation and being next to the current conductor, will form a field and tend to take a vertical position along the conductor.
In this case, it sounds like this: if you cover the solenoid in such a way that the fingers point to the direction of the current in the screws, then the protruding capital finger of the right hand will show the direction of the magnetic induction rows.
Various interpretations of the gimlet rule suggest that all its descriptions are adapted to various occasions their applications.
The right hand rule says::covering the element that is being examined in such a way that the fingers of the clenched fist show the vector of magnetic lines, with translational movement along the magnetic lines, the capital finger bent 90 degrees relative to the palm of the hand will show the direction of the current movement.
In the case where a moving conductor is given, the principle will have the following formulation: place the hand so that the field lines of force enter the palm vertically; the main finger of the hand, exposed vertically, will orient the direction of movement of this conductor, in this case, the other four exposed fingers will have the same direction as the induction current.
Its use is inherent in the calculation of coils in which an influence is formed on the current, which entails the formation of a countercurrent when needed.
AT real life A corollary of this principle also applies: if you stir the palm of your right hand so that the lines of the magnetic force field entered this palm, and point your fingers to the line of movement of charged particles along the protruding capital finger, then it is possible to indicate where the line of this force will be directed, which has a displacing effect on the conductor. In other words, the force that makes it possible to rotate the moment of force on the shaft of any engine operating with electric current.
Consider the rule: if you place the left palm so that the other four fingers show the direction of the current, then in this case the lines of induction will enter the palm at a right angle, and the turned away capital finger will show the vector of the existing force.
There is another notation. Orientation strength Ampere and Lorentz forces should indicate the exposed main finger of the left hand in the event that the remaining four fingers are placed in the direction of movement of positively and negatively charged elements of electric current, and the lines of induction of the formed field will vertically enter the palm. This invention is considered theoretical and practical explanation how motors and generators operate using electric current.
It can be concluded that knowledge of these rules and the ability to use them in practice allow you to create and invent electrical appliances and successfully work with them.
Video
This video will help you better understand what a magnetic field is.
What is the Left Hand Rule? You will find the answer in this video.
Magnetic field - Lorentz force.
Back view. radial artery; dorsal carpal branch of the radial artery; ulnar palmar artery of the thumb; dorsal metacarpal arteries; dorsal carpal branch of the ulnar artery; dorsum of the wrist...
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"RIGHT HAND RULE" in books
Right hand rule
From the book Universal Encyclopedic Reference author Isaeva E. L.The right hand rule Determines the direction of the induction current in a conductor moving in a magnetic field: if the palm of the right hand is positioned so that it includes the lines of magnetic induction, and the bent thumb is directed along the movement of the conductor, then four
Right hand rule
From the book Big Soviet Encyclopedia(PR) author TSBRight hand rule
From the AutoCAD 2009 student book. Tutorial author Sokolova Tatyana YurievnaRight hand rule When working in 3D space in AutoCAD, all coordinate systems are formed according to the right hand rule. It defines the positive direction of the Z-axis of the 3D coordinate system when the directions of the X and Y axes are known, as well as the positive direction
Right hand rule
From the AutoCAD 2009 book. Training course author Sokolova Tatyana YurievnaRight hand rule When working in 3D space in AutoCAD, all coordinate systems are formed according to the right hand rule. It defines the positive direction of the Z-axis of the three-dimensional coordinate system, given the directions of the X and Y axes, as well as the positive
Right Hand Rules*
From the C++ book by Hill MurrayRight Hand Rules* Here is a set of rules that you would do well to follow when learning C++. As you get more experienced, you can turn them into something that suits your line of work and your programming style. They are deliberately made
"PARALYSIS" OF THE RIGHT HAND
From the book Music and Medicine. On the example of German romance author Neumayr Anton"PARALYSIS" OF THE RIGHT HAND But already in mid-October, his mood returned to a "healthy balance". He liked the lessons with the musical director Dorn, and his mood improved when he invited Kristel to a new apartment, which he recently rented: “Kharita
Cultivation in the Right Hand Path
From the book Male Improvement sexual energy by Chia MantakCultivation on the Right Hand Path One method of the Right Hand Path that students of the Tao might wish to try is as follows. After going to bed early, wake up early in the morning sometime between midnight and half past six in the morning. At this time often
LESSON number 1. Topic: relaxation of the right hand.
From the book Psychological Self-Preparation for Hand-to-Hand Combat author Makarov Nikolai AlexandrovichLESSON number 1. Topic: relaxation of the right hand. All relaxation processes are easier to feel in one limb. For a right-hander, it's better to start with the right hand. Take your posture. The breath is soothing. Close your eyes. All attention to the right hand. Relax your muscles, relieve the slightest tension.
Chapter 94: Forbidden to use the right hand to wash.
by al-BukhariChapter 94: Forbidden to use the right hand to wash. 121 (153). It is reported that Abu Qatada, may Allah be pleased with him, said: “The Messenger of Allah, peace and blessings of Allah be upon him, said:“ When one of you drinks, let him not breathe into the vessel, but if he enters
Chapter 324: Laying the Right Hand on the Left
From the book of Mukhtasar "Sahih" (collection of hadiths) by al-BukhariChapter 324: Laying the Right Hand on the Left 403 (740). It is reported that Sahl bin Sa'd, may Allah be pleased with him, said: “People were ordered to put their right hand on their left during prayer.
Right forearm protection
From the book Fight Club: Combat Fitness for Men the author Atilov AmanProtection with the forearm of the right hand Technique: take a fighting stance. Place your right forearm at head level. a) b) Photo 122. Right forearm support Photo 123. Right forearm support protection
Release from the grip of the wrist of the right hand
the author Master ChoiRelease from gripping the wrist of the right hand The opponent grabs the wrist of your right hand with his right hand. Turn the brush of your right hand from bottom to top clockwise around the wrist of the opponent’s right hand so that the palm of your right hand rests on
From the book Hapkido for beginners the author Master ChoiExemption from grabbing the elbow of the right hand The opponent grabbed your right hand in the elbow area with his left hand. Raise up the right arm bent at the elbow so that the opponent's hand is on the inside of your arm. Then take a step back with your left foot,
Exemption from the capture of the elbow of the right hand
From the book Hapkido for beginners the author Master ChoiReleasing Right Elbow Grip Opponent has grabbed your right arm at elbow height with his left arm. Step back with your left foot. At the same time, raise your right arm bent at the elbow so that the opponent's arm is inside yours. Then do
Lesson 1 Topic: Relaxing the right hand
From the book Assault Battle GROM. Psychological preparation author Makhov Stanislav YurievichLesson 1 Topic: relaxation of the right hand All relaxation processes are easier to feel in one limb. For a right-hander, it's better to start with the right hand. Take your posture. The breath is soothing. Close your eyes. All attention to the right hand. Relax your muscles, relieve the slightest tension. AT
| Examples of some magnetic fields | field lines | Determining the direction of magnetic induction lines |
| Forward current field | The lines of magnetic induction of direct current are concentric circles lying in a plane perpendicular to the current. | The thumb of the right hand is directed along the current in the conductor, the conductor is wrapped around the conductor with four fingers, the direction in which the fingers are bent coincides with the direction of the magnetic induction line. |
| Circular current field |  | Four fingers of the right hand grasp the conductor in the direction of the current in it, then the bent thumb will indicate the direction of the line of magnetic induction. |
| Solenoid field (coils with current) | The end of the solenoid, from which the lines of magnetic induction come out, is its northern magnetic pole, the other end that the induction lines come in is the south magnetic pole. | It is determined similarly to the field of circular current. |
A magnetic field is detected by its effect on current-carrying conductors or a moving charged particle.
| Amp power | Lorentz force | |
| Definition | The force with which a magnetic field acts on a current-carrying conductor. | The force with which a magnetic field acts on a moving charged particle. |
| Formula |  |
|
| Direction | The rule of the left hand: if the left hand is positioned so that the lines of magnetic induction enter the palm, four outstretched fingers are directed along the current, then the thumb bent 90 degrees will indicate the direction of the Ampere force.  | Left hand rule: if the hand is positioned so that the lines of magnetic induction enter the palm, four extended fingers are directed in the direction of movement of a positively charged particle, then the thumb bent 90 degrees will indicate the direction of the Lorentz force.  |
| Force work | , where is the angle between the vectors and . | The Lorentz force does not do work on the particle and does not change its kinetic energy, it only bends the particle's trajectory, giving it centripetal acceleration. |
The nature of the motion of charged particles in a magnetic field.
1) A particle with a charge enters a magnetic field so that the vector is parallel, in this case, the particle moves in a straight line and uniformly.
2) A particle with a charge enters a magnetic field so that the vector is perpendicular to , in this case the particle moves in a circle in a plane perpendicular to the lines of induction.
3) A particle with a charge enters a magnetic field so that the vector makes some angle with the vector, in this case the particle moves in a spiral.
EXAMPLE OF SOLUTION OF THE PROBLEM ON THE MOTION OF A CHARGED PARTICLE IN A MAGNETIC FIELD
An electron moves in a uniform magnetic field with an induction of 4 . Find the period of its circulation.
Answer: 8.9
From the formula obtained when solving the problem, it follows that the period of revolution of a charged particle in a magnetic field does not depend on the speed with which it flies into the magnetic field and does not depend on the radius of the circle along which it moves.
ELECTROMAGNETIC INDUCTION
Electromagnetic induction- this is the phenomenon of the occurrence of an EMF of induction in a conducting circuit located in a changing magnetic field. If the conducting circuit is closed, then an induction current arises in it.
LAW OF ELECTROMAGNETIC INDUCTION (FARADAY'S LAW): The induction emf is equal in modulus to the rate of change magnetic flux.
or , where the number of turns in the circuit, the magnetic flux. 
The minus sign in the law reflects Lenz's rule: the induction current, with its magnetic flux, prevents a change in the magnetic flux by which it is caused.
Where is the surface area of the contour, the angle between the magnetic induction vector and the normal to the contour plane.
Where is the inductance of the conductor.
The inductance depends on the shape, dimensions of the conductor (the inductance of a straight conductor is less than the inductance of the coil), on magnetic properties environment surrounding the conductor.
| Methods for obtaining EMF induction | Formula | The nature of outside forces | Determining the direction of the inductive current |
| The conductor is in an alternating magnetic field | , where  | A vortex electric field that is generated by a changing magnetic field. | Algorithm: 1) Determine the direction of the external magnetic field. 2) Determine whether the magnetic flux is increasing or decreasing. 3) Determine the direction of the magnetic field of the induction current. If >0, then if<0, то 4) По правилу буравчика (правой руки) по направлению определить направление индукционного тока. |
| Changing the area of the contour | , where  |
||
| The position of the contour in the magnetic field changes (the angle changes) | , where | ||
| A conductor moves in a uniform magnetic field | , , where is the angle between | Lorentz force | Right hand rule: if the palm is positioned so that the magnetic induction vector enters the palm, the thumb extended coincides with the direction of the conductor's speed, then four extended fingers will indicate the direction of the inductive current. |
| Self-induction - the phenomenon of the occurrence of an EMF of induction in a conductor through which a changing current flows | or | Vortex electric field | The self-induction current is directed in the same direction as the current created by the source, if the current strength decreases, the self-induction current is directed against the current created by the source, if the current strength increases. |
An example of using the algorithm:
When solving problems for electromagnetic induction, Ohm's law is used: , and .
ENERGY OF THE MAGNETIC FIELD
VORTEX AND POTENTIAL FIELDS
| Potential fields: gravitational, electrostatic | Vortex (nonpotential) fields | ||
| magnetic | vortex electric | ||
| Field source | Stationary electric charge | Changing magnetic field | |
| Field indicator (object on which the field acts with some force) | Electric charge | Moving charge (electric current) | Electric charge |
| field lines | Open lines of electric field strength, start on positive charges | Closed lines of magnetic induction | Closed tension lines  |
Properties of the forces of potential fields:
1) The work of the forces of the potential field does not depend on the shape of the trajectory, but is determined only by the initial and final position of the body.
2) The work of the forces of the potential field when moving the body (charge) along a closed trajectory is equal to zero.
3) The work of the forces of the potential field is equal to the change in the potential energy of the body (charge), taken with a minus sign.
ELECTROMAGNETIC OSCILLATIONS
Electromagnetic vibrations- These are periodic changes in charge, current, voltage.
- formula for calculating the period of electromagnetic oscillations (Thomson formula).
FREE ELECTROMAGNETIC OSCILLATIONS are carried out in an oscillatory circuit consisting of an inductance coil and a capacitance capacitor. In order for oscillations to occur in the circuit, the capacitor must be charged by giving it a charge.
 |  |  | |||
| Charge | |||||
| Current strength | |||||
| Voltage |  |
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| Electric field energy | |||||
| Magnetic field energy | |||||
| total energy |  |
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 |  |
An ideal oscillating circuit is a circuit whose resistance is zero. In real circuits, therefore, the oscillations damp out, the energy communicated to the circuit is initially converted into heat.
FORCED ELECTROMAGNETIC OSCILLATIONS (AC)
Alternating current can be obtained by rotating a conducting loop in a magnetic field. In this case, the magnetic flux will change according to the sine or cosine law.
 |  |
Instantaneous value of the emf induction in the circuit
where maximum value of induction emf if the frame contains turns, then
RMS voltage and AC current called the voltage and strength of such a direct current at which the same amount of heat is released in the circuit as with a given alternating current. 
Voltmeters and ammeters included in the AC circuit measure the effective values.
AC LOADS
The current fluctuations lead the voltage fluctuations by
Current fluctuations lag behind voltage fluctuations byRESONANCE IN THE ELECTRIC CIRCUIT is a sharp increase in the amplitude of current and voltage fluctuations when the frequency of the alternating current supplied to the circuit coincides with the natural frequency of the circuit. Resonance is possible if a circuit containing inductance and capacitance and having a natural oscillation frequency , which depends only on and , is connected to an alternating current circuit with a frequency and resonant frequency 
on the wires of power lines, then they receive the voltage necessary for the consumer using step-down transformers.
ELECTROMAGNETIC WAVES
electromagnetic wave is an electromagnetic field propagating in space. The theory of electromagnetic waves was created by J. Maxwell in the 60s of the 19th century:
1) An alternating magnetic field generates an alternating electric field, an alternating electric field generates an alternating magnetic field, etc. This process lies in the formation of an electromagnetic wave.
2) The source of an electromagnetic wave is an oscillating (moving with acceleration) charge.
3) An electromagnetic wave in a vacuum propagates at the speed of light
4) Electromagnetic waves are transverse. Oscillations of the vectors and occur in mutually perpendicular planes that are perpendicular to the direction of the wave propagation velocity, i.e. mutually perpendicular.
5) The oscillations of the vectors and coincide in phase, i.e., they simultaneously vanish and simultaneously reach a maximum.
6) Electromagnetic waves can be reflected, refracted, they are characterized by the phenomena of interference, diffraction, dispersion, polarization.
For the first time, electromagnetic waves were discovered by the German physicist Heinrich Hertz in 1887. In his experiments, Hertz used an open oscillatory circuit, which is a segment of a metal conductor (Hertz's antenna or vibrator).
PRINCIPLES OF RADIO COMMUNICATIONS
Radio communication is the transmission of information using electromagnetic waves.
RADIO TRANSMITTER
RADIO
CLASSIFICATION OF RADIO WAVES
GEOMETRIC OPTICS
LAWS OF GEOMETRIC OPTICS
1) The law of rectilinear propagation of light.
Physics is far from the easiest subject, especially for those who have problems with it. It's no secret that not everyone gets along with sign systems, there are people who need to touch or at least see what they are studying. Fortunately, in addition to formulas and boring books, there are visual ways. For example, in this article we will consider how to determine the direction of the electromagnetic force with the help of the hand, using the well-known rule of the left hand.
This rule makes it a little easier, if not understanding the laws, then at least solving problems. True, only those who are at least a little versed in physics and its terms can apply it. Many textbooks have an image that explains very clearly how to use the left hand rule when solving problems. Physics, however, is clearly not the kind of science where you often have to put your hand on visual models, so develop your imagination.
First you need to know the direction of current flow in the part of the circuit where you are going to apply the left hand rule. Remember that a mistake in determining the direction will show you the opposite direction of the electromagnetic force, which will automatically nullify all your further efforts and calculations. As soon as you determine the direction of the current, position your left palm so that this course is indicated.
Next, you need to find the direction of the vector. If you have problems with this, it is worth brushing up your knowledge with the help of textbooks. When you find the desired vector, turn your palm so that this vector enters the open palm of the same left hand. The whole difficulty in applying the left hand rule lies precisely in whether you can correctly apply your knowledge to find constant vectors.
When you are sure that your palm is properly positioned, pull back so that its position becomes perpendicular to the direction of the current (where the rest of the fingers of the bunch are pointing). Remember that a finger is far from the most accurate indicator in physics, and in this case it only shows an approximate direction. If you are interested in accuracy, then after applying the left hand rule, use a protractor to bring the angle between the direction of the current and the direction indicated by the thumb to 90 degrees.
It should be remembered that the rule in question is not suitable for accurate calculations - it can only serve to quickly determine the direction of the electromagnetic force. In addition, its use requires additional conditions of the problem, and therefore is not always applicable in practice.
Naturally, it is not always possible to have a hand in the object under study, because sometimes it does not exist at all (in theoretical problems). In this case, in addition to imagination, other methods should be used. For example, you can draw a diagram on paper and apply the left hand rule to the drawing. The hand itself can also be schematically depicted in the figure for greater clarity. The main thing is not to get confused otherwise you can make mistakes. Therefore, do not forget to mark all the lines with signatures - then it will be easier for you to figure it out yourself.