How to understand the coming, refusal, and stay of Lenz s law

When the magnet does not move around the coil, the magnetic flux in the coil is zero, and this state is also "inertial" and does not want to be changed. For the sudden "intrusion" of the magnetic flux brought by the magnet, the coil "tries to block" this change. This is the law of Lenz's law of coming and going.

If the induced current is generated by the motion of the conductor that makes up the loop to cut the magnetic inductance line, then Lenz's law can be specifically expressed as: "The magnetic field force (ampere force) of the induced current on the moving conductor always resists (or hinders) the movement of the conductor." ”

This expression may be called a force formulation, where the "effect" of the induced current is the force of a magnetic field; The "cause" of the induced current is the movement of the conductor to cut the magnetic inductance line.

From the above expression of Lenz's law, it can be seen that Lenz's law does not directly point out the direction of the induced current, but only summarizes the principle of determining the direction of the induced current and gives the procedure for determining the induced current. To truly grasp it, it is necessary to have a correct understanding of the meaning of the expression, and to be proficient in the magnetic field of the current and the law of the force of the current in the magnetic field.

When a charged body enters the magnetic field, it is repulsed (rejected).

When a charged body exits the magnetic field, it is subjected to a gravitational pull (to stay).

It is to hinder external changes, if you want to come, I will hinder you, and if you want to go, I will hinder you. What do you want to do, I'm holding you back.

When the magnetic flux increases, the theorem states that it is going to hinder the increase. Decrease it to reduce its decrease!

Here's how I remember, it's simple: the opposite of change!

If the change in the external magnetic field increases the magnetic flux passing through me, then I have to find a way to reduce the increase.

Energy is conserved, and the energy is converted from kinetic energy into electrical energy through the magnetic field, and finally becomes thermal energy, so the velocity must be reduced.

The essence is the same as Le Chatre's principle. The mix of the two has unexpected results.

That is to say, the magnetic field generated is always a key to hinder the change of the original magnetic field (note: it is an obstacle, it can never be a block). Therefore, if the original magnetic field increases, the induced magnetic field must be opposite to it; If the original magnetic field decreases, the induced magnetic field must be in the same direction as it in order to act as a hindrance.

Come and refuse: It is another expression of Lenz's law, that is, if a magnet is close to you, the magnetic field becomes larger, and you want to prevent it from getting bigger, that is to refuse! If the magnet moves away from you, the induced magnetic field decreases, so you have to leave it (as if it is close to the magnet and has a tendency to expand).

This law is called Lenz's law to refuse to stay, but these two words are very familiar, another expression of Lenz's law, the law of Lenz in physics. When two people are together, the extended solution of Lenz's law is that the direction of the magnetic field and the original magnetic field of the induced current refuses to stay: the magnet is close to the coil and refuses to stay, increases but decreases, refuses to stay, increases and decreases.

Summary. So Lenz's law must be in the pathway to be impressed.

Hello classmates. Lenz's law: the flow direction of the induced current in a closed conductor loop always attempts to make the magnetic flux through the area of the loop excited by the induced current itself, which can be large enough to offset or compensate for the increase or decrease of the magnetic flux that causes the induced current.

That is, the flow direction of the induced current in the loop always makes the magnetic flux excitation of the induced current through the loop, and hinders the change of the original magnetic flux in the loop tumbling.

So Lenz's law must be in the pathway to be impressed.

No, the pathway cannot be used.

And there has to be a magnetic field.

The direction of the magnetic field should be consistent.

Lenz's law can only be used if these conditions are met.

If you have any questions, please feel free to consult me.

Does that mean that it can be used as long as there is a magnetic field? Or can it only be used when the magnetic flux changes?

There must also be an electric current.

There has to be a pathway in the magnetic field.

Otherwise, students who don't use electromagnetic effects.

Can you explain this question in detail? Just hope to be able to explain to me, why when the light bulb is on it, the switch is disconnected, and it will gradually dim and the jujube will not brighten first? What exactly is the function of that self-inductance coil?

How does it work?

Classmates are like this.

This is the characteristic of the spiral coil, which is called the same as the increase and the inverse decrease.

OK to see the first picture.

The upper resistance should be large when the path is passed.

In this way, when it is disconnected, it is equivalent to the coil is the power supply.

The voltage that the coil can provide is less than the voltage of the upper branch.

So it's getting darker slowly.

It won't flash that.

Can you understand this, classmates?

What does a low-frequency resistance high-frequency circuit look like? What about a high-frequency resistor low-frequency circuit? The greater the capacitive resistance, the greater or smaller the passing alternating current?

The greater the sense of resistance, the larger the passage of the current sketch shed, or the smaller the remembrance? Is it direct current or alternating current?

In the case of Figure B, why does it flash first when the switch is disconnected?

Large capacitors pass low frequency resistance to high frequency, and small capacitors pass high frequency resistance low frequency.

The inductance is resistive AC to DC.

The second diagram below the branch resistance is large.

What coil has a voltage that is greater than the voltage of a small bulb.

When disconnected, the coil gives the voltage, so it flashes.

Classmate, you can understand what I say.

Let's go into more detail.

The greater the resistance, the smaller the current, you know.

That's what this question is about.

When the second diagram is disconnected, it is equivalent to increasing the current.

It's big for a moment.

So it will flash a little.

Come and Reject and Stay: Another expression of Lenz's law, which is that if a magnet is close to you and the magnetic field becomes larger, and you want to prevent it from getting bigger, that is to refuse (the specific method of rejection is to make the coil smaller and away from the magnet). If the magnet moves away from you, the induced magnetic field decreases, so you have to leave it behind (i.e., if it is close to the magnet and has a tendency to expand).

What is Lenz's law?

Lenz's law is a basic principle of electromagnetism proposed by the British physicist James Lenz in 1831. According to Lenz's law, when the magnetic flux changes inside a conductor, an induced current is generated inside the conductor, and the direction of the induced current is to hinder the change of magnetic flux, that is, the direction of the induced current is always perpendicular to the direction of the magnetic flux change.

What is left behind by refusal?

In electricity and electromagnetism, Lenz's law is often used. When an electromagnetic wave passes through a conductor, it excites an induced current. According to Lenz's law, the direction of this induced current is reversed, thus canceling out the propagation of electromagnetic waves.

This is known as "retention", which is the phenomenon in which electromagnetic waves cannot remain in the conductor.

Application Scenarios Lenz's law has many practical application scenarios. For example, the induction cooker in modern science and technology uses the principle of Lenz's law. When an electromagnetic wave passes through the furnace's metal container, it generates an induced electric current that heats the metal inside the furnace.

In addition, Lenz's law is also widely used in equipment and mechanisms such as motors, generators, and electromagnetic wave resonators. In these devices, different aspects of Lenz's law are used to ensure proper working and efficient operation of the machine.

Conclusion Lenz's law is one of the basic principles in electromagnetism, which describes the law of induced current generated inside a conductor. In many practical application scenarios, we can see the application of Lenz's law. For example, induction cookers, motors, generators and other equipment have applied Lenz's law to ensure the normal operation of the machine and improve efficiency.

Lenz's law: The flow direction of the induced current in a closed conductor loop is always to make the magnetic flux through the area of the loop that the induced current excite itself, which can cancel out or compensate for the increase or decrease in the magnetic flux that causes the induced current.

That is, the flow direction of the induced current in the loop always makes the magnetic flux excited by the induced current pass through the circuit, and hinders the change of the original magnetic flux in the loop.

To refuse, stay, increase or decrease.

The more you want to be rotten, the more you reject you. It's the opposite of what you think.