The left hand rule is short. How the gimlet rule works in electrical engineering

Carrying interconnected electrical and magnetic energies. In space, they are located perpendicular to each other.

The main characteristics of the electromagnetic field are:

electric field strength, denoted by the index "H";

magnetic induction "B" (or magnetic field strength);

electromagnetic potential.

When an electric current passes around the conductor, it is formed. Its intensity (magnetic induction) depends on the magnitude and direction of the current. Using the mnemonic gimlet rule, the mutual dependence and direction of current and magnetic induction are determined.

Direction of gimlet rotation

The global industrial production has a tradition of massive use of threads with right-hand winding direction. It is cut into screws, bolts, screws, drills.

When the head of the fastener rotates in the clockwise direction, which repeats the movement of the Sun in the sky, screwing occurs. In order to disassemble the connection, it is necessary to rotate the head in the opposite direction.

Used by electrical engineering and vector algebra, the “Gimlet Rule” assumes just such an orientation of the thread. It should not be confused with the left-hand winding used, for example, in the gas industry or in individual cases of fastening elements in mechanical engineering.

Application of the rule

The figure below shows the location of the current conductor, gimlet and magnetic field lines.

1. Determination of the direction of magnetic induction by the current vector

If you mentally attach a gimlet parallel to the conductor in such a way that its translational movement during rotation by the handle coincides with the movement of current "I" in the conductor, then the gimlet handle will show the orientation of the magnetic induction lines "B".

2. Determining the direction of the current by the vector of magnetic induction

If the orientation of the magnetic induction formed from the current passing in the ring conductor is known, then it is necessary to position the gimlet in such a way that its translational movement coincides with this vector B. Then the rotation of the handle will indicate the direction of the current inside the conductor.

Right hand rule

The same relationships between current and magnetic induction can be determined in another way.

Four fingers on the right hand wrap around the conductor. In this case, the thumb protruding finger should indicate the direction of the current. Then the remaining fingers (from the index to the little finger) will indicate the orientation of the magnetic induction.

The rule of gimlet, right hand and left hand has found wide application in physics. Mnemonic rules are needed for easy and intuitive memorization of information. Usually this is the application of complex quantities and concepts to household and improvised things. The first to formulate these rules is the physicist Petr Buravchik. This rule belongs to the mnemonic and is closely related to the right hand rule, its task is to determine the direction of the axial vectors when known direction basic. This is what encyclopedias say, but we will talk about it in simple words, briefly and clearly.

Name Explanation

Most people remember the mention of this from the course of physics, namely the section of electrodynamics. It happened for a reason, because this mnemonic is often given to students to simplify the understanding of the material. In fact, the gimlet rule is used both in electricity, to determine the direction of a magnetic field, and in other sections, for example, to determine the angular velocity.

A gimlet is a tool for drilling small diameter holes in soft materials, for modern man it would be more customary to cite a corkscrew as an example.

Important! It is assumed that the gimlet, screw or corkscrew has a right-hand thread, that is, the direction of its rotation, when twisting, is clockwise, i.e. to the right.

The video below provides the full wording of the gimlet rule, be sure to watch it to understand the whole point:

How is the magnetic field related to the gimlet and hands

In problems in physics, when studying electrical quantities, one often encounters the need to find the direction of the current, along the vector of magnetic induction, and vice versa. Also, these skills will be required when solving complex problems and calculations related to the magnetic field of systems.

Before proceeding to the consideration of the rules, I want to recall that the current flows from a point with a large potential to a point with a lower one. It can be put more simply - the current flows from plus to minus.

The gimlet rule has the following meaning: when screwing the tip of the gimlet along the current direction, the handle will rotate in the direction of the vector B (the vector of magnetic induction lines).

The right hand rule works like this:

Put thumb as if you are showing "class!", then turn your hand so that the direction of the current and the finger match. Then the remaining four fingers will coincide with the magnetic field vector.

Visual analysis of the right hand rule:

To see this more clearly, conduct an experiment - scatter metal shavings on paper, make a hole in the sheet and thread the wire, after applying current to it, you will see that the shavings are grouped into concentric circles.

Magnetic field in the solenoid

All of the above is true for a straight conductor, but what if the conductor is wound into a coil?

We already know that when current flows around a conductor, a magnetic field is created, a coil is a wire coiled around a core or mandrel many times. The magnetic field in this case is amplified. A solenoid and a coil are basically the same thing. The main feature is that the lines of the magnetic field pass in the same way as in the situation with a permanent magnet. The solenoid is a controlled analogue of the latter.

The right hand rule for a solenoid (coil) will help us determine the direction of the magnetic field. If you take the coil in your hand so that four fingers look in the direction of current flow, then the thumb will point to vector B in the middle of the coil.

If you twist the gimlet along the turns, again in the direction of the current, i.e. from the "+" terminal to the "-" terminal of the solenoid, then the sharp end and the direction of movement as lies the magnetic induction vector.

In simple words, where you twist the gimlet, the lines of the magnetic field go there. The same is true for one turn (circular conductor)

Determining the direction of the current with a gimlet

If you know the direction of the vector B - magnetic induction, you can easily apply this rule. Mentally move the gimlet along the direction of the field in the coil with the sharp part forward, respectively, clockwise rotation along the axis of movement and show where the current flows.

If the conductor is straight, rotate the corkscrew handle along the specified vector so that this movement is clockwise. Knowing that it has a right-hand thread, the direction in which it is screwed in coincides with the current.

What is connected with the left hand

Do not confuse the gimlet and the left hand rule, it is necessary to determine the force acting on the conductor. The straightened palm of the left hand is located along the conductor. The fingers point in the direction of current flow I. Field lines pass through the open palm. The thumb coincides with the vector of force - this is the meaning of the rule of the left hand. This force is called the Ampere force.

You can apply this rule to a single charged particle and determine the direction of 2 forces:

1. Lorenz.
2. Ampere.

Imagine that a positively charged particle is moving in a magnetic field. The lines of the magnetic induction vector are perpendicular to the direction of its movement. You need to put the open left palm with your fingers in the direction of the charge movement, the vector B should penetrate the palm, then the thumb will indicate the direction of the vector Fa. If the particle is negative, the fingers look against the direction of the charge.

If at some point you were not clear, the video clearly shows how to use the left hand rule:

It's important to know! If you have a body and a force is acting on it that tends to turn it, turn the screw in this direction, and you will determine where the moment of force is directed. If we talk about the angular velocity, then the situation is as follows: when the corkscrew rotates in the same direction as the rotation of the body, it will screw in the direction of the angular velocity.

DETERMINATION OF THE DIRECTION OF THE MAGNETIC FIELD LINES

GIM RULE
for a straight conductor with current

- serves to determine the direction of magnetic lines (lines of magnetic induction)
around a straight current-carrying conductor.

If the direction of the translational movement of the gimlet coincides with the direction of the current in the conductor, then the direction of rotation of the gimlet handle coincides with the direction of the lines of the magnetic field of the current.

Suppose a conductor with current is located perpendicular to the plane of the sheet:
1. email direction current from us (to the sheet plane)

According to the gimlet rule, magnetic field lines will be directed clockwise.

Then, according to the gimlet rule, the magnetic field lines will be directed counterclockwise.

RIGHT HAND RULE
for a solenoid (i.e. coils with current)

- serves to determine the direction of magnetic lines (lines of magnetic induction) inside the solenoid.

If you grasp the solenoid with the palm of your right hand so that four fingers are directed along the current in the turns, then the thumb set aside will show the direction of the magnetic field lines inside the solenoid.

1. How do 2 coils with current interact with each other?

2. How are the currents in the wires directed if the interaction forces are directed as in the figure?

3. Two conductors are parallel to each other. Indicate the direction of current in the LED conductor.

I look forward to making decisions in the next lesson on "5"!

It is known that superconductors (substances that have almost zero electrical resistance at certain temperatures) can create very strong magnetic fields. Experiments have been made to demonstrate such magnetic fields. After cooling the ceramic superconductor with liquid nitrogen, a small magnet was placed on its surface. The repulsive force of the magnetic field of the superconductor was so high that the magnet rose, hovered in the air and hovered over the superconductor until the superconductor, when heated, lost its extraordinary properties.

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A MAGNETIC FIELD

- this is a special kind of matter, through which the interaction between moving electrically charged particles is carried out.

PROPERTIES OF A (STATIONARY) MAGNETIC FIELD

Permanent (or stationary) A magnetic field is a magnetic field that does not change with time.

1. Magnetic field created moving charged particles and bodies, conductors with current, permanent magnets.

2. Magnetic field valid on moving charged particles and bodies, on conductors with current, on permanent magnets, on a frame with current.

3. Magnetic field vortex, i.e. has no source.

are the forces with which current-carrying conductors act on each other.

.

is the force characteristic of the magnetic field.

The magnetic induction vector is always directed in the same way as a freely rotating magnetic needle is oriented in a magnetic field.

The unit of measurement of magnetic induction in the SI system:

LINES OF MAGNETIC INDUCTION

- these are lines, tangent to which at any point is the vector of magnetic induction.

Uniform magnetic field- this is a magnetic field, in which at any of its points the magnetic induction vector is unchanged in magnitude and direction; observed between the plates of a flat capacitor, inside a solenoid (if its diameter is much less than its length), or inside a bar magnet.

Magnetic field of a straight conductor with current:

where is the direction of the current in the conductor on us perpendicular to the plane of the sheet,
- the direction of the current in the conductor from us is perpendicular to the plane of the sheet.

Solenoid magnetic field:

Magnetic field of bar magnet:

- similar to the magnetic field of the solenoid.

PROPERTIES OF MAGNETIC INDUCTION LINES

- have direction
- continuous;
-closed (i.e. the magnetic field is vortex);
- do not intersect;
- according to their density, the magnitude of the magnetic induction is judged.

DIRECTION OF MAGNETIC INDUCTION LINES

- is determined by the gimlet rule or by the right hand rule.

Gimlet rule (mainly for a straight conductor with current):

Right hand rule (mainly for determining the direction of magnetic lines
inside the solenoid):

There are other possible options applying the rules of the gimlet and the right hand.

is the force with which a magnetic field acts on a current-carrying conductor.

The Ampere force module is equal to the product of the current strength in the conductor and the module of the magnetic induction vector, the length of the conductor and the sine of the angle between the magnetic induction vector and the direction of the current in the conductor.

The Ampere force is maximum if the magnetic induction vector is perpendicular to the conductor.

If the magnetic induction vector is parallel to the conductor, then the magnetic field has no effect on the conductor with current, i.e. Ampere's force is zero.

The direction of the Ampere force is determined by left hand rule:

If left hand position so that the component of the magnetic induction vector perpendicular to the conductor enters the palm, and 4 outstretched fingers are directed in the direction of the current, then the thumb bent 90 degrees will show the direction of the force acting on the conductor with current.

or

ACTION OF A MAGNETIC FIELD ON A LOOP WITH A CURRENT

A uniform magnetic field orients the frame (i.e., a torque is created and the frame rotates to a position where the magnetic induction vector is perpendicular to the plane of the frame).

An inhomogeneous magnetic field orients + attracts or repels the frame with current.

So, in the magnetic field of a direct current-carrying conductor (it is non-uniform), the current-carrying frame is oriented along the radius of the magnetic line and is attracted or repelled from the direct current-carrying conductor, depending on the direction of the currents.

Remember the topic "Electromagnetic phenomena" for grade 8:

Right hand rule

When a conductor moves in a magnetic field, a directed movement of electrons is created in it, that is, an electric current, which is due to the phenomenon of electromagnetic induction.

For determining directions of electron movement Let's use the well-known rule of the left hand.

If, for example, a conductor located perpendicular to the drawing (Figure 1) moves along with the electrons contained in it from top to bottom, then this movement of electrons will be equivalent to an electric current directed from bottom to top. If at the same time the magnetic field in which the conductor moves is directed from left to right, then to determine the direction of the force acting on the electrons, we will have to put the left hand with the palm to the left so that the magnetic lines of force enter the palm, and with four fingers up (against the direction of movement conductor, i.e. in the direction of the "current"); then the direction of the thumb will show us that the electrons in the conductor will be affected by a force directed from us to the drawing. Consequently, the movement of electrons will occur along the conductor, i.e., from us to the drawing, and the induction current in the conductor will be directed from the drawing to us.

Picture 1. The mechanism of electromagnetic induction. By moving the conductor, we move together with the conductor all the electrons enclosed in it, and when moving in a magnetic field of electric charges, a force will act on them according to the left hand rule.

However, the rule of the left hand, applied by us only to explain the phenomenon of electromagnetic induction, turns out to be inconvenient in practice. In practice, the direction of the induction current is determined right hand rule(Figure 2).

Figure 2. Right hand rule. The right hand is turned with the palm towards the magnetic lines of force, the thumb is directed in the direction of the movement of the conductor, and four fingers show in which direction the induction current will flow.

Right hand rule is that, if you place your right hand in a magnetic field so that the magnetic lines of force enter the palm, and the thumb indicates the direction of movement of the conductor, then the remaining four fingers will show the direction of the induction current that occurs in the conductor.

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A simple explanation of the gimlet rule

Name Explanation

Most people remember the mention of this from the course of physics, namely the section of electrodynamics. It happened for a reason, because this mnemonic is often given to students to simplify the understanding of the material. In fact, the gimlet rule is used both in electricity, to determine the direction of a magnetic field, and in other sections, for example, to determine the angular velocity.

A gimlet is a tool for drilling small diameter holes in soft materials, for a modern person it would be more common to use a corkscrew as an example.

Important! It is assumed that the gimlet, screw or corkscrew has a right-hand thread, that is, the direction of its rotation, when twisting, is clockwise, i.e. to the right.

The video below provides the full wording of the gimlet rule, be sure to watch it to understand the whole point:

How is the magnetic field related to the gimlet and hands

In problems in physics, when studying electrical quantities, one often encounters the need to find the direction of the current, along the vector of magnetic induction, and vice versa. Also, these skills will be required when solving complex problems and calculations related to the magnetic field of systems.

Before proceeding to the consideration of the rules, I want to recall that the current flows from a point with a large potential to a point with a lower one. It can be put simply - the current flows from plus to minus.

The gimlet rule has the following meaning: when screwing the tip of the gimlet along the current direction, the handle will rotate in the direction of the vector B (the vector of magnetic induction lines).

The right hand rule works like this:

Place your thumb as if you are showing "class!", Then turn your hand so that the direction of the current and the finger match. Then the remaining four fingers will coincide with the magnetic field vector.

Visual analysis of the right hand rule:

To see this more clearly, conduct an experiment - scatter metal shavings on paper, make a hole in the sheet and thread the wire, after applying current to it, you will see that the shavings are grouped into concentric circles.

Magnetic field in the solenoid

All of the above is true for a straight conductor, but what if the conductor is wound into a coil?

We already know that when current flows around a conductor, a magnetic field is created, a coil is a wire coiled around a core or mandrel many times. The magnetic field in this case is amplified. A solenoid and a coil are basically the same thing. The main feature is that the lines of the magnetic field pass in the same way as in the situation with a permanent magnet. The solenoid is a controlled analogue of the latter.

The right hand rule for a solenoid (coil) will help us determine the direction of the magnetic field. If you take the coil in your hand so that four fingers look in the direction of current flow, then the thumb will point to vector B in the middle of the coil.

If you twist the gimlet along the turns, again in the direction of the current, i.e. from the "+" terminal to the "-" terminal of the solenoid, then the sharp end and the direction of movement as lies the magnetic induction vector.

In simple words, where you twist the gimlet, the lines of the magnetic field go there. The same is true for one turn (circular conductor)

Determining the direction of the current with a gimlet

If you know the direction of the vector B - magnetic induction, you can easily apply this rule. Mentally move the gimlet along the direction of the field in the coil with the sharp part forward, respectively, clockwise rotation along the axis of movement and show where the current flows.

If the conductor is straight, rotate the corkscrew handle along the specified vector so that this movement is clockwise. Knowing that it has a right-hand thread, the direction in which it is screwed in coincides with the current.

What is connected with the left hand

Do not confuse the gimlet and the left hand rule, it is necessary to determine the force acting on the conductor. The straightened palm of the left hand is located along the conductor. The fingers point in the direction of current flow I. Field lines pass through the open palm. The thumb coincides with the vector of force - this is the meaning of the rule of the left hand. This force is called the Ampere force.

You can apply this rule to a single charged particle and determine the direction of 2 forces:

Imagine that a positively charged particle is moving in a magnetic field. The lines of the magnetic induction vector are perpendicular to the direction of its movement. You need to put the open left palm with your fingers in the direction of the charge movement, the vector B should penetrate the palm, then the thumb will indicate the direction of the vector Fa. If the particle is negative, the fingers look against the direction of the charge.

If at some point you were not clear, the video clearly shows how to use the left hand rule:

It's important to know! If you have a body and a force is acting on it that tends to turn it, turn the screw in this direction, and you will determine where the moment of force is directed. If we talk about the angular velocity, then the situation is as follows: when the corkscrew rotates in the same direction as the rotation of the body, it will screw in the direction of the angular velocity.

It is very easy to master these methods of determining the direction of forces and fields. Such mnemonic rules in electricity greatly facilitate the tasks of schoolchildren and students. Even a full kettle will deal with a gimlet if it has opened wine with a corkscrew at least once. The main thing is not to forget where the current flows. I repeat that the use of a gimlet and the right hand is most often successfully used in electrical engineering.

You probably don't know:

Rules of the left and right hand

The right hand rule is the rule used to determine the magnetic induction vector of a field.

This rule also has the names "rule of gimlet" and "rule of the screw", due to the similarity of the principle of operation. It is widely used in physics, as it allows, without the use of special instruments or calculations, to determine the most important parameters - angular velocity, moment of force, moment of impulse. In electrodynamics, this method allows you to determine the vector of magnetic induction.

gimlet rule

The rule of a gimlet or screw: if the palms of the right hand are placed so that it coincides with the direction of the current in the conductor under study, then the translational rotation of the gimlet handle (thumb of the palm) will directly indicate the vector of magnetic induction.

In other words, it is necessary to screw in a drill or a corkscrew with your right hand to determine the vector. There are no particular difficulties in mastering this rule.

There is another version of this rule. Most often, this method is simply called the “right hand rule”.

It sounds like this: in order to determine the direction of the lines of induction of the generated magnetic field, you need to take the conductor with your hand so that the thumb left at 90 ° shows the direction of the current flowing through it.

There is a similar option for the solenoid.

In this case, you should grab the device so that the fingers of the palm coincide with the direction of the current in the turns. The protruding thumb in this case will show where the magnetic field lines come from.

Right hand rule for a moving conductor

This rule will also help in the case of conductors moving in a magnetic field. Only here it is necessary to act somewhat differently.

The open palm of the right hand should be positioned so that the field lines of force enter it perpendicularly. The outstretched thumb should indicate the direction of movement of the conductor. With this arrangement, the outstretched fingers will coincide with the direction of the induction current.

As we can see, the number of situations where this rule really helps is quite large.

The first rule of the left hand

It is necessary to place the left palm in such a way that the field induction lines enter it at a right angle (perpendicular). The four outstretched fingers of the palm should coincide with the direction of the electric current in the conductor. In this case, the extended thumb of the left palm will show the direction of the force acting on the conductor.

In practice, this method allows you to determine the direction in which a conductor with an electric current passing through it, placed between two magnets, will begin to deviate.

The second rule of the left hand

There are other situations where you can use the left hand rule. In particular, to determine the forces with a moving charge and a stationary magnet.

Another rule of the left hand says: The palm of the left hand should be positioned in such a way that the lines of induction of the created magnetic field enter into it perpendicularly. The position of the four outstretched fingers depends on the direction of the electric current (along the movement of positively charged particles, or against negative ones). The protruding thumb of the left hand in this case will indicate the direction of the Ampere force or the Lorentz force.

The advantage of the rules of the right and left hand lies precisely in the fact that they are simple and allow you to accurately determine important parameters without the use of additional instruments. They are used in various experiments and tests, and in practice when it comes to conductors and electromagnetic fields.

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The gimlet rule or the right hand rule was first formulated by Peter Gimlet. It determines the direction of the magnetic field strength, which

is in a straight line to a current-carrying conductor.

The main rule that is used in variants of the screw or gimlet rule and in the formulation of the right hand rule is the rule for choosing the direction of the cross product and bases. It is quite simple to remember: if a gimlet with a right-hand thread is screwed in the direction of the current, then the direction of rotation of the handle of the gimlet itself coincides with the direction of the magnetic field, which is excited by the current (Fig. 1).

It is necessary to grab the conductor with the right hand so that the thumb shows the direction of the current, then the remaining fingers will show the lines of magnetic induction that go around this conductor and the fields that are created by the current, as well as the direction of the magnetic induction vector, which is directed everywhere tangentially to the lines. If a current is passed through the wire, then a magnetic field will also arise around the wire.

If the wire consists of several turns and the axes of these turns coincide, then it is called a solenoid (Fig. 2).

rice. 2

The magnetic field is excited when current passes through one turn (winding) of the solenoid. Its direction depends on the direction of the current.

The presented field of the solenoid rings is very similar to the field of a permanent magnet. The direction of the solenoid field lines can be determined using the gimlet rule, as well as the right hand rule. A freely rotating magnetic needle, placed near a conductor with current, which forms a magnetic field, tends to take a perpendicular position of the plane that runs along it.

The right hand rule for a solenoid is that if the solenoid is clasped with the right hand so that four fingers point in the direction of the current in the coils, then the thumb will point in the direction of the magnetic field lines in the solenoid itself.

With the translational movement of the gimlet coinciding with the direction of the current in the conductor, then the rotational movements of the gimlet handle will indicate the direction of the magnetic field lines that arise around the conductor. If the right hand is placed so that it includes all the lines of force of the magnetic field, and the big one is placed in the direction of the conductor, then four fingers will indicate the direction of the induction current.

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A simple explanation of the gimlet rule

Name Explanation

Most people remember the mention of this from the course of physics, namely the section of electrodynamics. It happened for a reason, because this mnemonic is often given to students to simplify the understanding of the material. In fact, the gimlet rule is used both in electricity, to determine the direction of a magnetic field, and in other sections, for example, to determine the angular velocity.

A gimlet is a tool for drilling small diameter holes in soft materials, for a modern person it would be more common to use a corkscrew as an example.

Important! It is assumed that the gimlet, screw or corkscrew has a right-hand thread, that is, the direction of its rotation, when twisting, is clockwise, i.e. to the right.

The video below provides the full wording of the gimlet rule, be sure to watch it to understand the whole point:

How is the magnetic field related to the gimlet and hands

In problems in physics, when studying electrical quantities, one often encounters the need to find the direction of the current, along the vector of magnetic induction, and vice versa. Also, these skills will be required when solving complex problems and calculations related to the magnetic field of systems.

Before proceeding to the consideration of the rules, I want to recall that the current flows from a point with a large potential to a point with a lower one. It can be put simply - the current flows from plus to minus.

The gimlet rule has the following meaning: when screwing the tip of the gimlet along the current direction, the handle will rotate in the direction of the vector B (the vector of magnetic induction lines).

The right hand rule works like this:

Place your thumb as if you are showing "class!", Then turn your hand so that the direction of the current and the finger match. Then the remaining four fingers will coincide with the magnetic field vector.

Visual analysis of the right hand rule:

To see this more clearly, conduct an experiment - scatter metal shavings on paper, make a hole in the sheet and thread the wire, after applying current to it, you will see that the shavings are grouped into concentric circles.

Magnetic field in the solenoid

All of the above is true for a straight conductor, but what if the conductor is wound into a coil?

We already know that when current flows around a conductor, a magnetic field is created, a coil is a wire coiled around a core or mandrel many times. The magnetic field in this case is amplified. A solenoid and a coil are basically the same thing. The main feature is that the lines of the magnetic field pass in the same way as in the situation with a permanent magnet. The solenoid is a controlled analogue of the latter.

The right hand rule for a solenoid (coil) will help us determine the direction of the magnetic field. If you take the coil in your hand so that four fingers look in the direction of current flow, then the thumb will point to vector B in the middle of the coil.

If you twist the gimlet along the turns, again in the direction of the current, i.e. from the "+" terminal to the "-" terminal of the solenoid, then the sharp end and the direction of movement as lies the magnetic induction vector.

In simple words, where you twist the gimlet, the lines of the magnetic field go there. The same is true for one turn (circular conductor)

Determining the direction of the current with a gimlet

If you know the direction of the vector B - magnetic induction, you can easily apply this rule. Mentally move the gimlet along the direction of the field in the coil with the sharp part forward, respectively, clockwise rotation along the axis of movement and show where the current flows.

If the conductor is straight, rotate the corkscrew handle along the specified vector so that this movement is clockwise. Knowing that it has a right-hand thread, the direction in which it is screwed in coincides with the current.

What is connected with the left hand

Do not confuse the gimlet and the left hand rule, it is necessary to determine the force acting on the conductor. The straightened palm of the left hand is located along the conductor. The fingers point in the direction of current flow I. Field lines pass through the open palm. The thumb coincides with the vector of force - this is the meaning of the rule of the left hand. This force is called the Ampere force.

You can apply this rule to a single charged particle and determine the direction of 2 forces:

Imagine that a positively charged particle is moving in a magnetic field. The lines of the magnetic induction vector are perpendicular to the direction of its movement. You need to put the open left palm with your fingers in the direction of the charge movement, the vector B should penetrate the palm, then the thumb will indicate the direction of the vector Fa. If the particle is negative, the fingers look against the direction of the charge.

If at some point you were not clear, the video clearly shows how to use the left hand rule:

It's important to know! If you have a body and a force is acting on it that tends to turn it, turn the screw in this direction, and you will determine where the moment of force is directed. If we talk about the angular velocity, then the situation is as follows: when the corkscrew rotates in the same direction as the rotation of the body, it will screw in the direction of the angular velocity.

It is very easy to master these methods of determining the direction of forces and fields. Such mnemonic rules in electricity greatly facilitate the tasks of schoolchildren and students. Even a full kettle will deal with a gimlet if it has opened wine with a corkscrew at least once. The main thing is not to forget where the current flows. I repeat that the use of a gimlet and the right hand is most often successfully used in electrical engineering.

You probably don't know:

A MAGNETIC FIELD

- this is a special kind of matter, through which the interaction between moving electrically charged particles is carried out.

PROPERTIES OF A (STATIONARY) MAGNETIC FIELD

Permanent (or stationary) A magnetic field is a magnetic field that does not change with time.

1. Magnetic field created moving charged particles and bodies, conductors with current, permanent magnets.

2. Magnetic field valid on moving charged particles and bodies, on conductors with current, on permanent magnets, on a frame with current.

3. Magnetic field vortex, i.e. has no source.

are the forces with which current-carrying conductors act on each other.

.

is the force characteristic of the magnetic field.

The magnetic induction vector is always directed in the same way as a freely rotating magnetic needle is oriented in a magnetic field.

The unit of measurement of magnetic induction in the SI system:

LINES OF MAGNETIC INDUCTION

- these are lines, tangent to which at any point is the vector of magnetic induction.

Uniform magnetic field- this is a magnetic field, in which at any of its points the magnetic induction vector is unchanged in magnitude and direction; observed between the plates of a flat capacitor, inside a solenoid (if its diameter is much less than its length), or inside a bar magnet.

Magnetic field of a straight conductor with current:

where is the direction of the current in the conductor on us perpendicular to the plane of the sheet,
- the direction of the current in the conductor from us is perpendicular to the plane of the sheet.

Solenoid magnetic field:

Magnetic field of bar magnet:

- similar to the magnetic field of the solenoid.

PROPERTIES OF MAGNETIC INDUCTION LINES

- have direction
- continuous;
-closed (i.e. the magnetic field is vortex);
- do not intersect;
- according to their density, the magnitude of the magnetic induction is judged.

DIRECTION OF MAGNETIC INDUCTION LINES

- is determined by the gimlet rule or by the right hand rule.

Gimlet rule (mainly for a straight conductor with current):

Right hand rule (mainly for determining the direction of magnetic lines
inside the solenoid):

There are other possible applications of the gimlet and right hand rules.

is the force with which a magnetic field acts on a current-carrying conductor.

The Ampere force module is equal to the product of the current strength in the conductor and the module of the magnetic induction vector, the length of the conductor and the sine of the angle between the magnetic induction vector and the direction of the current in the conductor.

The Ampere force is maximum if the magnetic induction vector is perpendicular to the conductor.

If the magnetic induction vector is parallel to the conductor, then the magnetic field has no effect on the conductor with current, i.e. Ampere's force is zero.

The direction of the Ampere force is determined by left hand rule:

If the left hand is positioned so that the component of the magnetic induction vector perpendicular to the conductor enters the palm, and 4 outstretched fingers are directed in the direction of the current, then the thumb bent 90 degrees will show the direction of the force acting on the conductor with current.

or

ACTION OF A MAGNETIC FIELD ON A LOOP WITH A CURRENT

A uniform magnetic field orients the frame (i.e., a torque is created and the frame rotates to a position where the magnetic induction vector is perpendicular to the plane of the frame).

An inhomogeneous magnetic field orients + attracts or repels the frame with current.

So, in the magnetic field of a direct current-carrying conductor (it is non-uniform), the current-carrying frame is oriented along the radius of the magnetic line and is attracted or repelled from the direct current-carrying conductor, depending on the direction of the currents.

Remember the topic "Electromagnetic phenomena" for grade 8:

class-fizika.narod.ru

Determining the direction of magnetic field lines. The gimlet rule. Right hand rule

GIM RULE for a straight conductor with current

- serves to determine the direction of magnetic lines (lines of magnetic induction)
around a straight current-carrying conductor.

If the direction of the translational movement of the gimlet coincides with the direction of the current in the conductor, then the direction of rotation of the gimlet handle coincides with the direction of the lines of the magnetic field of the current.

Suppose a conductor with current is located perpendicular to the plane of the sheet:
1. email direction current from us (to the sheet plane)

According to the gimlet rule, magnetic field lines will be directed clockwise.

Then, according to the gimlet rule, the magnetic field lines will be directed counterclockwise.

RIGHT HAND RULE for solenoid, i.e. coils with current

- serves to determine the direction of magnetic lines (lines of magnetic induction) inside the solenoid.

If you grasp the solenoid with the palm of your right hand so that four fingers are directed along the current in the turns, then the thumb set aside will show the direction of the magnetic field lines inside the solenoid.

1. How do 2 coils interact with each other with current?

2. How are the currents in the wires directed if the interaction forces are directed as in the figure?

3. Two conductors are parallel to each other. Indicate the direction of current in the LED conductor.

Looking forward to the next lesson on "5"!

It is known that superconductors (substances that have almost zero electrical resistance at certain temperatures) can create very strong magnetic fields. Experiments have been made to demonstrate such magnetic fields. After cooling the ceramic superconductor with liquid nitrogen, a small magnet was placed on its surface. The repulsive force of the magnetic field of the superconductor was so high that the magnet rose, hovered in the air and hovered over the superconductor until the superconductor, when heated, lost its extraordinary properties.

Right and left hand rule in physics: application in everyday life

Entering adulthood, few people remember the school physics course. However, sometimes it is necessary to delve into the memory, because some knowledge gained in youth can greatly facilitate the memorization of complex laws. One of these is the right and left hand rule in physics. Its application in life allows you to understand complex concepts (for example, to determine the direction of the axial vector with a known basis). Today we will try to explain these concepts and how they work in a language accessible to a simple layman who graduated a long time ago and forgot unnecessary (as it seemed to him) information.

Read in the article:

The wording of the gimlet rule

Piotr Buravchik is the first physicist to formulate the left hand rule for various particles and fields. It is applicable both in electrical engineering (it helps to determine the direction of magnetic fields), and in other areas. It will help, for example, to determine the angular velocity.

Gimlet rule (right hand rule) - this name is not associated with the name of the physicist who formulated it. More the name relies on a tool that has a certain direction of the auger. Usually, a gimlet (screw, corkscrew) has a so-called. the thread is right-handed, the drill enters the ground clockwise. Consider the application of this statement to determine the magnetic field.

You need to clench your right hand into a fist, raising your thumb up. Now we slightly unclench the other four. They show us the direction of the magnetic field. In short, the gimlet rule has the following meaning - by screwing the gimlet along the direction of the current, we will see that the handle rotates in the direction of the line of the magnetic induction vector.

The right and left hand rule: application in practice

In considering the application of this law, let's start with the right hand rule. If the direction of the magnetic field vector is known, with the help of a gimlet one can do without knowledge of the law of electromagnetic induction. Imagine that the screw moves along the magnetic field. Then the direction of current flow will be "along the thread", that is, to the right.

Let's pay attention to the permanent controlled magnet, the analogue of which is the solenoid. At its core, it is a coil with two contacts. It is known that the current moves from "+" to "-". Based on this information, we take the solenoid in the right hand in such a position that 4 fingers indicate the direction of the current flow. Then the outstretched thumb will indicate the vector of the magnetic field.

Application of the right hand rule for a solenoid

The left hand rule: what can be determined using it

Do not confuse the rules of the left hand and gimlet - they are designed for completely different purposes. With the help of the left hand, two forces can be determined, or rather, their direction. This:

Let's try to figure out how it works.

Application for ampere force

The left hand rule for Ampère's power: what it is

Place the left hand along the conductor so that the fingers are directed in the direction of current flow. The thumb will point in the direction of the Ampère force vector, and in the direction of the hand, between the thumb and forefinger, the magnetic field vector will be directed. This will be the left hand rule for the ampere force, the formula of which looks like this:

Left hand rule for the Lorentz force: differences from the previous one

We arrange the three fingers of the left hand (thumb, index and middle) so that they are at right angles to each other. The thumb, directed in this case to the side, will indicate the direction of the Lorentz force, the index finger (pointed down) - the direction of the magnetic field (from the north pole to the south), and the middle one, located perpendicular to the side of the big one - the direction of the current in the conductor.

The formula for calculating the Lorentz force can be seen in the figure below.

Conclusion

Having dealt once with the rules of the right and left hand, the dear reader will understand how easy it is to use them. After all, they replace the knowledge of many laws of physics, in particular, electrical engineering. The main thing here is not to forget the direction of current flow.

With the help of hands, you can determine many different parameters

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Instruction

Read in the textbook for the eighth grade what the rules of the right screw sound like. This rule is also called the gimlet rule or the right hand rule, which indicates its semantic nature. So, one of the formulations of the right screw rule says that in order to understand how the magnetic field located around a current-carrying conductor is directed, it is necessary to imagine that the translational movement of a rotating screw coincides with the direction of the current in the conductor. The direction of rotation of the screw head in this case should indicate the direction of the magnetic field of a straight current-carrying conductor.

Please note that the wording and understanding of this rule becomes clearer if we imagine a gimlet instead of a screw. Then the direction of rotation of the gimlet handle is taken as the direction of the magnetic field.

Remember the solenoid. As you know, it is an inductor wound on a magnetic core. The coil is connected to a current source, as a result of which a uniform magnetic field of a certain direction is formed inside it.

Draw a solenoid schematically on a piece of paper from the side of its end. In fact, you will get an image of a circle. Indicate on the circle representing the turns of the coil, the direction of the current in the conductor in the form of an arrow (clockwise). Now it remains to understand in the direction of the current where the lines of the magnetic field are directed. In this case, they can be directed either from you or towards you.

Imagine that you are tightening some kind of screw or screw, rotating it in the direction of current flow in the solenoid. The translational movement of the screw shows the direction of the magnetic field inside the solenoid. If the direction of the current is clockwise, then the vector of the magnetic field is directed away from you.

If you are not comfortable applying abstract rules using a gimlet handle or a screw in every problem, use the right screw rule in the formulation of the right hand rule. The operation of this rule is the same, only the method of determining the direction of induction of a magnetic field or current in a coil differs.

Draw the end of the solenoid again. Show the direction of the current in the coil (counterclockwise). Attach the right edge of the right hand to the drawn circle so that the little finger is in contact with the circle and four fingers point to the direction of the current in the conductors. Extend your thumb 90 degrees, pointing towards you and matching the direction of the magnetic field in the solenoid.

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