Calculation of Ampere force by electromagnetic induction
Publish: 2021-05-04 18:23:50
1. First question
1: first of all, what the teacher said is very correct. You're right about equivalence. The problem is our definition of potential“ A positively charged particle always tends to move in the direction of a lower potential. " It is not difficult to see that the potential is set with positive electricity as the reference. But electric potential energy is not like gravitational potential energy. The gravitational potential energy decreases (or increases) in the same direction. If this thing let go, it will fall down, and so will that one
but charged particles are different. High potential does not necessarily mean high energy. A positively charged particle moves to a place where the potential is low because the potential energy is low for it. The negative particle will move to the place with high potential, because the potential energy is low for it. Therefore, because there are two kinds of charged particles, and we only set a set of potential definition standards for them, there is a phenomenon of inequivalence. In fact, if we look at it in terms of energy connectivity, it is equivalent
2 it is said in the book that when the motion direction of negative electron and positron is the same, the force direction is opposite. And according to what you said, the current to the right on the electrical conctor. That is to say, if there is a positron, it moves to the right. If it is a negative electron, it should move to the left. Now the direction of motion is opposite, so the natural direction of force is the same. It's all up. If there is only one particle, according to this problem, the positive particle will make a counter clockwise uniform circular motion, and the negative particle will make a clockwise uniform circular motion. But when they are at the top and bottom of the trajectory, the forces are the same. It's like the electron in a metal conctor in your topic
the fact is that in the same magnetic field, the forces of different charges moving in different directions are the same. Or do you think that the same charge moving in different directions in the same magnetic field should be forced in different directions? In the same magnetic field, should different charges moving in the same direction be forced in different directions? If your answer is yes, then if the two add up, the negative will be positive
(never mind what your teachers and classmates say. Maybe some of them really understand, but I believe more of them are just endorsements. They don't think as much as you. Such a person is also the one I hated most in those years.)
I'm not familiar with the following questions. I need to remember. Maybe I'll give you an answer in the evening.
1: first of all, what the teacher said is very correct. You're right about equivalence. The problem is our definition of potential“ A positively charged particle always tends to move in the direction of a lower potential. " It is not difficult to see that the potential is set with positive electricity as the reference. But electric potential energy is not like gravitational potential energy. The gravitational potential energy decreases (or increases) in the same direction. If this thing let go, it will fall down, and so will that one
but charged particles are different. High potential does not necessarily mean high energy. A positively charged particle moves to a place where the potential is low because the potential energy is low for it. The negative particle will move to the place with high potential, because the potential energy is low for it. Therefore, because there are two kinds of charged particles, and we only set a set of potential definition standards for them, there is a phenomenon of inequivalence. In fact, if we look at it in terms of energy connectivity, it is equivalent
2 it is said in the book that when the motion direction of negative electron and positron is the same, the force direction is opposite. And according to what you said, the current to the right on the electrical conctor. That is to say, if there is a positron, it moves to the right. If it is a negative electron, it should move to the left. Now the direction of motion is opposite, so the natural direction of force is the same. It's all up. If there is only one particle, according to this problem, the positive particle will make a counter clockwise uniform circular motion, and the negative particle will make a clockwise uniform circular motion. But when they are at the top and bottom of the trajectory, the forces are the same. It's like the electron in a metal conctor in your topic
the fact is that in the same magnetic field, the forces of different charges moving in different directions are the same. Or do you think that the same charge moving in different directions in the same magnetic field should be forced in different directions? In the same magnetic field, should different charges moving in the same direction be forced in different directions? If your answer is yes, then if the two add up, the negative will be positive
(never mind what your teachers and classmates say. Maybe some of them really understand, but I believe more of them are just endorsements. They don't think as much as you. Such a person is also the one I hated most in those years.)
I'm not familiar with the following questions. I need to remember. Maybe I'll give you an answer in the evening.
2. A lot of physical processes are like this, change can proce new things, very philosophical. This problem can be accelerated left and decelerated right. Note that it does not have to be uniform speed, the problem is mainly easy to analyze
3. Inced current is like friction. I call it from the power, not the initiative. Just like friction, it can only be proced with traction or initial velocity
if there is current in the electrified coil, an ampere force will be generated and the coil will move under this ampere force. However, it is obvious that when the coil moves, there will be speed and a reverse inced electromotive force (Lenz's law) will be generated. The reverse electromotive force will generate current, and the current direction is reversed, So there will be a reverse ampere force. The last ampere force is equal to the first ampere force in the opposite direction. But I say that the model you mentioned generally does not exist. In general, the topic will give you a conctor bar, which is placed in a circuit with power supply. The conctor rod will be accelerated by Ampere force at first under the uniform magnetic field force, and then uniform when the ampere force generated by itself is as large as the original ampere force. The inced electromotive force of this speed is equal to the inced electromotive force of the power supply, and it is relative, so there is no current in the circuit. What provides the speed of the conctor bar? Energy conservation, the energy of the conctor power source becomes the kinetic energy of the conctor rod.
if there is current in the electrified coil, an ampere force will be generated and the coil will move under this ampere force. However, it is obvious that when the coil moves, there will be speed and a reverse inced electromotive force (Lenz's law) will be generated. The reverse electromotive force will generate current, and the current direction is reversed, So there will be a reverse ampere force. The last ampere force is equal to the first ampere force in the opposite direction. But I say that the model you mentioned generally does not exist. In general, the topic will give you a conctor bar, which is placed in a circuit with power supply. The conctor rod will be accelerated by Ampere force at first under the uniform magnetic field force, and then uniform when the ampere force generated by itself is as large as the original ampere force. The inced electromotive force of this speed is equal to the inced electromotive force of the power supply, and it is relative, so there is no current in the circuit. What provides the speed of the conctor bar? Energy conservation, the energy of the conctor power source becomes the kinetic energy of the conctor rod.
4. It is not the magnetic field proced by the inced current that exerts a force on the inced current, but the magnetic field proced by the current formed by the rotating ring B exerts a force on the inced current in ring a (or the magnetic field proced by the inced current in ring a) It's very winding)
analysis: 1. When the charged B-ring rotates clockwise, it forms a counter clockwise current (because the B-ring has a negative charge). According to the ampere rule, it can be judged that the magnetic field generated by the B-ring is perpendicular to the paper inside and outward and inward outside
2. Because ring B accelerates its rotation, the magnetic field is constantly enhanced, so the inced current will be generated in ring a:
3. According to Lenz's law, the direction of the magnetic field generated by the inced current of ring a is to hinder the enhancement of the magnetic field of ring B, so the magnetic field of ring a is perpendicular to the inside of the paper
4. It can be seen that in the region between ab rings, the magnetic fields generated by the two rings are inward, so AB repels each other and a expands outward.
analysis: 1. When the charged B-ring rotates clockwise, it forms a counter clockwise current (because the B-ring has a negative charge). According to the ampere rule, it can be judged that the magnetic field generated by the B-ring is perpendicular to the paper inside and outward and inward outside
2. Because ring B accelerates its rotation, the magnetic field is constantly enhanced, so the inced current will be generated in ring a:
3. According to Lenz's law, the direction of the magnetic field generated by the inced current of ring a is to hinder the enhancement of the magnetic field of ring B, so the magnetic field of ring a is perpendicular to the inside of the paper
4. It can be seen that in the region between ab rings, the magnetic fields generated by the two rings are inward, so AB repels each other and a expands outward.
5. Look at the direction of power wiring, power voltage, conctor speed<
firstly, when the generated current and the power supply current arrive, it will promote
while on the contrary, it will resist. The generated voltage exceeds the power supply voltage, and on the contrary, press the direction of generated current. The initial speed has nothing to do with the power supply, it has something to do with the speed. It only tells the initial speed, acceleration!
firstly, when the generated current and the power supply current arrive, it will promote
while on the contrary, it will resist. The generated voltage exceeds the power supply voltage, and on the contrary, press the direction of generated current. The initial speed has nothing to do with the power supply, it has something to do with the speed. It only tells the initial speed, acceleration!
6. Of course, the original magnetic field, because the ampere force comes from the original magnetic field. The landlord loves to think.
7. Well, you're talking about the law of conservation of momentum. The law of momentum is that the change of the system momentum is equal to the impulse of the combined external force. When ad enters the magnetic field, cutting the magnetic inction line will proce a dynamic electromotive force, which will generate a current in the circuit. The current in CD is equal to that in AB, and the direction is opposite. Therefore, the force of the magnetic field on AB and CD is equal, and the direction is opposite, That is, ad and CD as a whole, the combined external force is 0, which satisfies the law of conservation of momentum
8. There is a uniform magnetic field B on the plane of the vertical guide rail in the middle of the mutually parallel long straight guide rail. The distance between the guide rails is L. the conctor bar is placed in the vertical guide rail. Under the action of external force, the conctor bar moves to the right at a uniform speed v. the resistance of the conctor bar is r, and other resistances are ignored
1. The conctor bar cuts the magnetic field to generate the inced electromotive force, which is e = BLV.
2. The current in the circuit is I = E / r = BLV / R
3. The ampere force on the conctor bar is f a = ILB = B ^ 2L ^ 2V / R
4. The work done by Ampere force is w a = f a, VT = - B ^ 2L ^ 2V ^ 2T / R. The work done by overcoming ampere force is B ^ 2L ^ 2V ^ 2T / R
5. Work done by current w = EIT = B ^ 2L ^ 2V ^ 2T / R
calculated from above, w a = w electricity
1. The conctor bar cuts the magnetic field to generate the inced electromotive force, which is e = BLV.
2. The current in the circuit is I = E / r = BLV / R
3. The ampere force on the conctor bar is f a = ILB = B ^ 2L ^ 2V / R
4. The work done by Ampere force is w a = f a, VT = - B ^ 2L ^ 2V ^ 2T / R. The work done by overcoming ampere force is B ^ 2L ^ 2V ^ 2T / R
5. Work done by current w = EIT = B ^ 2L ^ 2V ^ 2T / R
calculated from above, w a = w electricity
9.
In electromagnetic inction, the energy of Ampere force to do work comes from the power source to convert other forms of energy into electric energy:
in the electromagnetic inction phenomenon, the external force changes the magnetic flux of the closed circuit and converts the mechanical energy into electric energy. By overcoming the ampere force to do work, the electric energy is converted into other forms of energy (internal energy, chemical energy, mechanical energy, etc.) how much work does ampere force do, How much energy is converted into other forms of energy
according to the kinetic energy theorem, we can know that the kinetic energy changes with the work done by the resultant force, and the kinetic energy changes as much as the work done by the resultant force. Joule heat is only related to the work done by Ampere force. When we calculate this kind of problems in the future, we should remember that in electromagnetic inction, internal energy is related to the work done by Ampere force, and kinetic energy is related to the work done by resultant force
extended data:
the direction of Ampere force is determined by the left hand rule. For any shape of current under the force of non-uniform magnetic field, the current can be divided into many current elements I Δ 50. The magnetic field B at each current element can be regarded as a uniform magnetic field, and the ampere force is Δ F=I Δ L·Bsin α， Adding these ampere force vectors together is the force on the whole current
It should be noted that when the current direction is the same as or opposite to the magnetic field direction, namely α= 0 or π The current is not affected by the force of magnetic field. When the current direction is perpendicular to the magnetic field direction, the maximum ampere force on the current is f = bil. B is the magnetic inction intensity, I is the current intensity, and l is the length of the wire perpendicular to the magnetic inction line10. 1. I'm not from Guangzhou, so I can't provide these services. You can apply directly to the bank, which is not difficult...
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2. According to your business scope, the rate should be 2%, which is stipulated by UnionPay, and there is not much room for floating among different banks...
3. If the installation is successful, you can accept the debit cards with UnionPay logo from various banks, As for whether to accept credit card (i.e. overdraft consumption card), it should be determined according to the settlement account you use. If it's an indivial settlement account, it can't accept credit card. If it's a corporate settlement account, it can accept credit card
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