This is the static electricity from the generator itself. "The short circuit voltage between the two poles of the generator disappears" because the internal resistance of the generator itself is large and the positive and negative electrons will not be coupled immediately. . If the voltage is on the internal resistance, the voltage test pen will have no voltage; “There is electricity again after disconnection” because the pairing is not completed, so there is still electricity; “No matter how much I shake or stop; I can't go back to this state. " This is related to the angle. The more magnetic lines of force the wire cuts per unit of time, the greater the energy.
Rule of the left motor, principle diagram of the rule of right generator
The principle of cutting magnetic field lines to generate current is as follows:
When a conductor in a closed circuit moves to cut off themagnetic field lines in the magnetic field, a current will be generated in the conductor. This phenomenon is called electromagnetic induction, and the current generated is called induced. current.
Two conditions must be met to generate an induced current: 1. A part of the conductor that closes the circuit 2. A movement that cuts the magnetic field lines; If the circuit is not closed, only an induced voltage will be generated, but no induced current will be generated.
What is magnetic field line breakage?
Cutting magnetic field lines is how a conductor moves in a magnetic field. When we study the problem, we can imagine the magnetic field lines as real lines and the conductor as a knife. will be more practical.
Application of cutting magnetic induction lines:
1 Electromagnetic induction
If the If one. Part of the conductor moves to cut the magnetic field lines in the magnetic field, the electrons in the conductor will be subject to the Lorentz force. The Lorentz force is a non-electrostatic force that can cause an electric potential difference, thereby generating a current. . This current is called induced current.
2. Generator
The principle of a generator is electromagnetic induction. The basic structure of a generator is a magnetic field and a coil rotating in the magnetic field. field. Its energy conversion involves converting mechanical energy into electrical energy.
3. DC Generator
AC generator and DC generator generate alternating current inside the generator, while DC generator generates direct current outside. , and what is generated externally by the alternator is alternating current.
What aret the right hand rule?
In electromagnetism, the right-hand rule primarily determines direction independently of force. You can use the direction of the palm and fingers of your right hand to memorize the direction of the current generated when the wire intersects the magnetic field lines.
That is: spread your right hand flat so that your thumb is perpendicular to the other four fingers, and they are all in the same plane as the palm. Put your right hand in the magnetic field and let the magnetic field lines enter from the center of the palm (when the magnetic field lines are straight, it is equivalent to the palm of the hand facing the N pole), and the thumb points to the direction of movement of the wire, then the direction pointed by the four fingers is the current induced in the direction of the wire (kinetic electromotive force).
The history of the development of electricity
Left hand rule zuǒshǒudìngzé left hand rule The left hand is flat, so the thumb is perpendicular to the other four fingers, and they are all in the same plane as the palm. Put your left hand in the magnetic field and let the magnetic field lines penetrate vertically into the palm of your hand (align the palm of your hand with the N pole and the back of your hand with the S pole). The four fingers point inward. the direction of the current (i.e. the direction of movement of the positive charge). Then the direction of the thumb is the direction of the force exerted on the driver. Principle used in electric motors: When you draw both the magnetic field lines of the magnet and the magnetic field lines of the current, the two magnetic field lines are intertwined. According to vector addition, the directions of the magnetic field lines of the magnet and. the current is ins the same direction, the magnetic field lines become dense in the opposite direction, the magnetic field lines become sparse. A characteristic of magnetic field lines is that each magnetic field line in the same direction repel each other! Where the magnetic field lines are dense, the pressure is high, and where the magnetic field lines are sparse, the pressure is low. So the pressure on the two sides of the current is different, pushing the current to one side. The direction of your thumb is the direction of that pressure. Right-hand rule Right-hand rule For the cross product of a vector, we define A×B=C. Note that the order of A and B cannot be reversed. Suppose the direction of vector A is along the back of the hand. and vector B is in the direction of the four fingers, then The direction of vector C is the direction of the thumb (perpendicular to the plane formed by A and B). It's the rule of the handRIGHT. Keep your right hand flat so that your thumb is perpendicular to the other four fingers and in the same plane as your palm. Put your right hand in the magnetic field. If the magnetic field lines enter the palm of your hand perpendicularly (when the magnetic field lines are straight, this is equivalent to the palm of your hand facing the N pole) and your thumb points toward the direction the wire is moving, then the direction pointed by the four fingers is the direction of the current induced in the wire. In electromagnetism, the right-hand rule primarily determines direction independently of force. If this is related to strength, then it all depends on the left-hand rule. That is, use the left hand for strength and use the right hand for other rules. ---For more details, see the photos http://baike.baidu.com/view/73484.html http://baike.baidu.com/view/163305.html
As soon as possible Because Before therehad a concrete knowledge of electricity, it was known that dynamofish delivered electric shocks. According to an ancient Egyptian book written in 2750 BC, these fish were known as the "Thunderbringer of the Nile" and were the protectors of all other fish. About 2,500 years later, Greeks, Romans, Arab naturalists, and Arab medical scholars reappeared with records of electric fish.
In 1832, the Frenchman Pixie built the world's first experimental generator. In 1850, the British Swan invented a carbon paper filament bulb. In 1866, German Siemens produced a practical generator.
On October 21, 1879, the American Edison (and the British Joseph Swan) both studied carbon filament light bulbs. Edison tested the white color of carbon filament more than a thousand times. Incandescent light bulbs were put into practice, which is why it is said that Edison inventedelectric light.
Jack Kilby independently invented the integrated circuit in 1958 and Robert Noyce in 1959. Today, a large number of electronic components such as transistors, diodes, resistors, capacitors, etc. can be assembled into a single integrated circuit.
The real application of electricity took place in the late 18th and 19th centuries. It was only in the 20th and 21st centuries that it truly entered the homes of ordinary people.
Detailed informationElectrification phenomenon
Electrification by friction is a physical phenomenon in which objects are charged by friction. The triboelectricity step involves using two different insulators to rub against each other, so that their outermost electrons receive enough energy to transfer. After electrification by friction, both insulators must carry the same amount of electricity opposed.
Electrostatic adsorption means that when a statically charged object approaches a small, non-static object, the free charge on the surface of the small object is transferred, inducing the electrical property opposite to that of the electrostatically charged object, and is attracted to it. Attached to statically charged objects. Using the principle of electrostatic attraction of light and small objects, the adsorption effect of industrial dust can be achieved.
Electrostatic induction is a phenomenon in which the charges of a conductor are redistributed within a conductor under the action of an external electric field. It was described by the British scientist John Canton and the Swedish scientist John Carl Wilke in 1753 and 1762 respectively. Year of discovery.
Electrostatic shielding means that for a grounded cavity conductor, the external electric field will not affect objects insideeur of the cavity, and the electric field of the charged body in the cavity will not affect objects outside the cavity.
Electrostatic shielding is widely used. For example, metal mesh covering the exterior of electronic instruments and metal sheaths wrapped around cables are used to prevent external electric fields from affecting the interior. It should be noted that if the external electric field is an alternating electric field, the conditions for electrostatic shielding are no longer met. See also electromagnetic shielding.
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