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1.In acids, salts, and other solutions, only negative ions are moving, because the negative ions move to the positive electrode, and the positive ions do not move, so they are positively charged, and it is not the positive charge that moves past.
2.Potential difference.
3.Electric field in wires? It depends on how you arrange the wires, straight or looped or wound.
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1.When the free electrons in the conductor move, the nucleus does not move, the electrons are negatively charged, and during the motion, the relative positive charge moves, and the direction of the current is the opposite direction of the electron movement (the motion is relative).
2.Although it is a conductor, it is inevitable that there is a certain impedance, although the impedance is very small, but as long as there is a current, the small impedance will also form a certain voltage difference (called the potential difference), and with the voltage difference, the electric field will be on the line.
3.The arrangement of the wires will also affect the electric field distribution of the wires, if it is a parallel line, then e=u d, if it is of other shapes, it is relatively complicated, and it needs to use calculus in advanced mathematics.
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One end has electrons decreasing and is positively charged, while the other end has a corresponding increase in electrons and is negatively charged.
When an electric current is generated, an electric field exists. The electric field is the medium of over-distance action and is the medium of the electric field force.
The electric field in a wire is an infinite number of ring-shaped circles centered on the wire.
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1 There are three possible reasons for the formation of electric current in a conductor, in a metal conductor there are free electrons moving, another is the movement of a positive charge, and another is what you call a positive and negative charge moving in opposite directions at the same time.
2. Potential difference. 3 The electric field varies according to the current in the wire.
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3. The electric field in the wire is parallel to the surface of the wire along the wire (the free charge is distributed on the surface of the wire and affects the electric field, making it so). Assuming that the electric field lines are not parallel to the surface of the wire, the directional movement of the electric charge will inevitably accumulate in a certain part of the wire, and eventually produce a discharge, which is an impossible phenomenon.
2. Keep in mind that the free charge in the conductor will only be distributed on the surface of the conductor, and if there is an external electric field, the electric field in the conductor must be 0 (if it is not 0, the free charge will move and eventually cancel it to zero, all of which is done in an instant. )
1. Only free electrons move in the conductor. Both positive and negative ions move in the solution. If there are electrons from other places to supplement (other conductors, earth, etc.), there will still be a positive and negative balance, otherwise it will be charged (only the insulator can be charged, and the charge of the conductor will move away instantaneously).
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Let's take a look at the concept first, not the current density.
It's the current intensity of Hezhongzen.
This should be related to the condition of the training key of the wire itself. To put it simply, it has something to do with his resistance and his voltage resistance. If. More than he allows, big words. It's easy to get hot.
causes the insulation to burn and catch fire.
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The allowable current density of the conductor refers to the index under certain conditions, which is related to the conductor material and the heat dissipation environment. If the heat accumulated beyond the allowable value is greater than the heat emitted, it will continue to heat up, and you will know what the result of the last calendar year is.
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In a conductor, the current refers to the movement of electrons in a conductor. There are a large number of free electrons present in the conductor that can move through the conductor under the action of an applied electric field, forming an electric current. The magnitude of the current is related to factors such as the number of electrons, the speed at which the electrons are moving, and the electric field force experienced by the electrons.
In a DC circuit, the magnitude of the current is constant, whereas in an AC circuit, both the magnitude and direction of the current change with time. In addition, the current in a conductor is also affected by factors such as conductor material, cross-sectional area, length, and temperature. Specifically, the resistance of a conductor is related to factors such as conductor material, cross-sectional area, length, and temperature, the greater the resistance, the lower the current in the conductor.
In conclusion, the current in a conductor is formed by the movement of free electrons in the conductor under the action of an applied electric field, and its magnitude and direction are affected by factors such as electric field force, conductor material, cross-sectional area, length, and temperature.
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Summary. The magnitude of the current is inversely proportional to the resistance of the conductor, and a good conductor can carry a larger current.
The magnitude of the current is related to the conductor itself. The resistance of different conductors is different, and according to Ohm's law, the magnitude of the current is inversely proportional to the resistance cavity, that is, the larger the current, the smaller the resistance of the conductor to keep the current stable. As a result, a better conductor is generally able to carry a larger current, while a worse conductor may result in a smaller current.
Hope this meets your needs.
You've done a great job! Can you elaborate on that?
The magnitude of the current is inversely proportional to the resistance of the conductor, and a good conductor can carry a larger current.
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When an electric current flows through a conductor, a magnetic field is created around the conductor. A conductor is a substance that has a very low resistivity and is prone to conducting electric current. The presence of a large number of freely moving charged particles in a conductor is called a carrier.
The magnetic field is a special substance that cannot be seen or touched, and the magnetic field is not composed of atoms or molecules, but the magnetic field exists. The magnetic field has the radiative properties of wave particles. There is a magnetic field around the magnet, and the interaction between the magnets is mediated by the magnetic field, so the two magnets can act without contact.
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When a conductor cuts a magnetic inductance line, the free charge (usually electrons) in the conductor moves directionally under the action of the Loren magnetic force, forming an electric current.
The free charge in the conductor will first move with the conductor, and it also has a velocity that is the same as the speed of the conductor, when this velocity is not parallel to the direction of the magnetic inductance line, the free charge will move directionally along the direction of the conductor by the action of the Loren magnetic force, forming an electric current.
When the free charge has a velocity in the direction of the conductor, the free charge is subjected to a Lorenic magnetic force perpendicular to the conductor, which macroscopically reflects the ampere force received by the sedan as a charged conductor rod in the magnetic field that hinders the sail grinding before the movement.
In addition, the electric current is formed due to the directional movement of the charge.
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1. When the resistance of the electric limb friend increases, under the condition that the voltage does not change, according to Ohm's law, the current becomes larger.
2. When the resistance increases, the voltage becomes larger according to Ohm's law when the current remains unchanged.
3. When the resistance increases, the current becomes smaller according to Ohm's law under the condition that the electrodissipative voltage dissipation remains unchanged.
4. When the resistance increases, the current becomes larger according to Ohm's law under the condition that the voltage remains unchanged.
The resistance of a conductor to an electric current is called the resistance of the conductor. Resistance is a physical quantity that in physics indicates the magnitude of a conductor's action on the resistance of an electric current. The greater the resistance of a conductor, the greater the resistance of the conductor to the current.
Different conductors, the resistance is generally different, and resistance is a property of the conductor itself. The resistance of a conductor is usually represented by the letter r, and the unit of resistance is ohm, referred to as ohm, and the symbol is .
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There are two necessary conditions for the generation of current in a conductor: there is a conductive path and there is a potential difference.
The conditions that need to be met for the formation of the current with the pin:
There are two conditions: the generation of electromotive force and the creation of a closed loop through the load. Scientifically, the amount of electricity passing through any cross-section of a conductor per unit of time is called current intensity, referred to as current, the current symbol is i, and the unit is ampere (a), referred to as "ampere".
That is, the tendency of electrons to move, which can overcome the resistance of the conductor resistance to the current and make the charge flow in the closed conductor loop. This action is due to the corresponding physical or chemical effect, and is usually accompanied by the conversion of energy, because the energy consumed when the current flows through the conductor (except superconductors) must be compensated by the energy that generates the electromotive force.
Power Zone: If the EMF occurs only in a portion of the conductor circuit, that area is called the power zone. There is also resistance in the power supply area, which is called the internal resistance of the power supply.
The energy consumed in the conductor circuit outside the power supply area is directly related to the electromagnetic field in the conductor, but the energy of the electromagnetic field still comes from the power supply.
Classification of conductors:
Category 1 Conductors:
Metals are the most common type of conductor. The nucleus and inner electrons in the metal form the atomic solid, which is regularly arranged into a lattice, while the valence electrons in the outer shell easily break free from the shackles of the nucleus and become free electrons, which constitute conductive carriers. The concentration of free electrons in the metal is very large, about 10 to the power of 22 per cubic centimeter, so the resistivity of the metal conductor is small and the electrical conductivity is large.
The first stupid volcanic tour class II conductor:
The solution of the electrolyte or the molten electrolyte known as the electrolyte is also a conductor whose carriers are positive and negative ions. Most pure liquids can also be dissociated, but to a very small extent, so they are not conductors. For example, the resistivity of pure water is as high as 104 ohms, which is 1010-1012 times greater than the resistivity of metal.
However, if a little electrolyte is added to pure water, the resistivity will be greatly reduced and it will become a conductor.
Gas conductors: Ionized gases can also conduct electricity, and the carriers in them are electrons and positive and negative ions. In general, gases are good insulators.
With the help of external causes, such as heating or irradiation with X-rays, rays or ultraviolet light, the gas molecules can be dissociated, so that the ionized gas becomes a conductor. The conductivity of ionized gases has a lot to do with the applied voltage, and is often accompanied by physical processes such as acoustic luminescence.
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If there is a voltage at the end of the conductor, the current will be generated in the conductor. () Land demolition.
a.That's right. b.Mistake.
The answer is b
The current at both ends of the resistance is proportional to the voltage, that is, the higher the voltage, the greater the current, when the voltage is greater than the voltage that the resistance can bear, the resistance will be burned out and the circuit will be broken, and the current at this time is zero. The formula is i=u r. It is the current = voltage resistance.
It's very simple, but let's talk about your thoughts - first of all, there are very few good conductors of electricity in objects made of molecules (chemistry is not good, hehe) that can conduct electricity: free electrons, charged ions. So it's fair to say that I basically disagree with you. >>>More
It's not that there is no electric current, but there is an electric current, which is the directional movement of free electrons in the conductor, and the positive charge in the atom is the nucleus, and the nucleus does not move, but the free electrons that can move. >>>More
Of course, it can be said that the size is large, but the voltage in engineering is used to say high and low. >>>More
The battery has internal resistance, which is equivalent to a small resistance inside the battery and the circuit in series, when the external resistance value is increased, the external partial voltage becomes larger, and the voltmeter measures the external voltage, so the value will become larger, dare to raise their own doubts, and it is so sharp, you are very promising, hehe.