How 1 The magnetic effect of electric current 2 The phenomenon of electromagnetic induction 3 The in

Magnetic Effect of Electric Current:

1 Oersted's experiment proves that there is a magnetic field around the energized wire.

Application: 1 Electromagnetic relay: It is essentially a switch that is controlled by an electromagnet. Its function can realize long-distance operation, using low voltage, weak current to control high voltage, strong current. Automatic control is also possible.

2**Basic principle: vibration, strong and weak change current, vibration.

Electromagnetic induction phenomenon:

1. When a part of the conductor of the closed circuit is cut in the magnetic field, an electric current is generated in the conductor, which is called electromagnetic induction, and the current generated is called induced current.

2. Conditions for generating induced current: The circuit must be closed; Only a part of the circuit conductor is in a magnetic field; This part of the conductor does the cutting magnetic inductance line movement.

3. The direction of the induced current: It is related to the direction of the conductor movement and the direction of the magnetic inductance line. (right-hand rule).

4 In the phenomenon of electromagnetic induction, mechanical energy is converted into electrical energy.

5 The principle of the generator is made based on the phenomenon of electromagnetic induction.

Interaction between electricity and magnetism: 1. The effect of magnetic field on electric current.

1.Contents: An energized conductor is subjected to a force in a magnetic field.

2.Direction of force: 1) It is related to the direction of the current and the direction of the magnetic field.

2) The direction of force is perpendicular to the direction of the current and perpendicular to the direction of the magnetic inductance line.

3.Determination of direction: the left-handed rule.

Second, the energized coil is stressed in the magnetic field.

1.Rotation occurs when the rectangular coil is in place, and rotation occurs only when it is not in the equilibrium position.

2.When the coil plane is perpendicular to the magnetic inductance line, the position of the coil plane at this time is called the equilibrium position.

3.In order to make the coil rotate continuously in the magnetic field, it is necessary to immediately change the direction of the current in the coil when the coil just deviates from the equilibrium position due to inertia, and the commutator can complete this task.

4.The direction of rotation of the energized coil in the magnetic field is determined by the direction of the current and the direction of the magnetic field, when a certain direction is changed, the direction of force of the energized coil changes, and when both directions change, the direction of rotation does not change.

3. DC motor.

Definition: A motor powered by a DC power source is called a DC motor.

2.Principle: An energized coil is subjected to a force in a magnetic field.

3.Conversion of energy: Electrical energy is converted into mechanical energy.

4.Construction: magnet, coil, commutator, brush, etc.

1: Magnetic effect of electric current: When there is an electric current passing through the wire, there is a magnetic field around the wire.

2: Electromagnetic induction: Electromagnetic energy can magnetize iron.

3: Interaction of electricity and magnetism:"The Right Hand Law"The direction of the thumb is the direction of the current, and the direction of rotation clockwise around the wire is the direction of the magnetic field lines.

The magnetic effect of electric current is that electricity produces magnetism Judgment method: right-hand spiral rule.

The induction phenomenon of electromagnetism is magnetism and electricity Judgment method: right-hand determination of responsibility and Lenz's law.

The interaction between electricity and magnetism refers to the simultaneous existence of the magnetic effect of electric current and the inductive phenomenon of electromagnetism.

1. The magnetic effect of electric current was discovered by Oersted. One day in 1820, a professor of physics at the University of Copenhagen in Denmark, Oak Shout was giving a lecture on electrical experiments to his students. I saw that he connected the two ends of the voltaic stack with a wire, and hung the magnetic needle on the wire.

2. "Look, the magnetic needle has rotated and deviated from the north and south poles!" A schoolgirl named Margretel said in amazement. This fortuitous phenomenon excites Professor Auster.

3. Oster used a lot of voltaic stacks to make a large "experimental device for the deflection of magnetic needles affected by electric current". He decided to change the direction of the wires and the magnetic needles, from crossing each other at right angles to parallel and side by side. He turned the wire at a 90° angle so that it was parallel to the magnetic needle, in a north-south direction.

At the moment when the power was turned on, the magnetic needle quickly rotated, from north-south to east-west, and after shaking it slightly, it stopped. When the power is cut off, the magnetic needle returns to its original north-south orientation.

4. This experiment proves that the current can indeed act on the magnetic needle. On this basis, Oster published his famous ** "On the Magnetic Needle's Current Striking a Real Beam", which he called "the magnetic effect of electric current". In honor of Oersted, the unit of magnetic field strength was named "Oersted".

1. The typical application of the current magnetic effect is electromagnets and electromagnetic relays, which make the iron core difficult to generate magnetism by energizing the coil.

2. Current magnetic effect: when there is a current flowing in the wire, a toroidal magnetic field centered on the wire will be formed around the wire. The direction of the magnetic inductance line and the current square direction form a right-hand spiral rule.

When the direction of the right thumb is the direction of current, the direction of movement of the other four fingers is the direction of the magnetic inductance line.

The difference between the magnetic effect of electromagnetic induction and electric current is that the phenomenon is different, the principle is different, and the discoverer is different.

First, the phenomenon is different.

1. Electromagnetic induction: The phenomenon of electromagnetic induction is a conductor placed in a changing magnetic flux, which will produce electromotive force.

2. The magnetic effect of the current: The magnetic effect of the current is that the wire with the current is passed through it, and a magnetic field is generated around it.

Second, the principle is different.

1. Electromagnetic induction: The principle of electromagnetic induction is that when a part of a closed circuit is used by a conductor to cut magnetic inductance lines in a magnetic field, an electric current will be generated in the conductor.

2. The magnetic effect of electric current: The principle of the magnetic effect of electric current is that each molecule in a magnetic substance has a microscopic current, and the circular current of each molecule forms a small magnet. In magnetic matter, these currents are arranged regularly along the direction of the magnetic axis, thus appearing as a current rotating around the magnetic axis, and the current in the magnet interacts with the current in the conductor to cause the magnet to rotate.

3. Finding people are different.

1. Electromagnetic induction: Michael Faraday is generally considered to have discovered electromagnetic induction in 1831.

2. The magnetic effect of electric current: Danish physicist Hans Oster discovered the magnetic effect of electric current at night one day in April 1820.

The magnetic effect of electric current refers to the phenomenon that when an electric current passes through a conductor, a magnetic field is generated around it. According to Ampere's law, the wire through which the current passes will form a toroidal magnetic field around it, and the direction of the magnetic field is determined by the right-hand rule.

Electromagnetic induction refers to the presence of an electromotive force in a conductor, and when the magnetic flux in the conductor changes, it causes an induced electromotive force in the conductive body. Faraday's law of electromagnetic induction tells us that when a conductor is crossed by magnetic flux, an electromotive force is generated at both ends of it, and the magnitude of the electromotive force is proportional to the rate of the change in magnetic flux.

There is a close connection between the magnetic effect of electric current and electromagnetic induction. The law of electromagnetic induction is based on the magnetic effect of electric current, because a magnetic field can only be generated when an electric current passes through a conductor, and a change in the magnetic field causes electromagnetic induction. Since a magnetic field is generated when an electric current passes through a conductor, an induced electromotive force is generated when the magnetic field inside the conductor changes.

This induced electromotive force can be calculated by the law of electromagnetic induction, as long as the rate of change of the magnetic flux is known.

In addition, the magnetic effect of electric current and electromagnetic induction are very important in many applications. For example, electric motors work on the basis of magnetic effects and electromagnetic induction of electric currents. When the current passes through the coil of the motor, the magnetic field around the coil will change with the change of current, resulting in electromagnetic induction in the coil, which will produce a torque that causes the motor to rotate.

In conclusion, the magnetic effect of electric current and electromagnetic induction are very important and closely related physical phenomena. They play an important role in many occasions in our daily lives. <>

Magnetic effect of electric current: Anything that is electrically charged.

The flow of wires can be a phenomenon of magnetic fields around them. In layman's terms, it is called electricity and magnetism.

Electromagnetic induction: refers to a conductor placed in a changing magnetic flux that generates an electromotive force. If this conductor is closed into a loop, the electromotive force drives the flow of electrons, resulting in an induced current. In layman's terms, it is magnetism and electricity.

These two phenomena are a process that reverses each other.

A typical application of the magnetic effect of electric current is an electromagnet, an electromagnetic relay that generates magnetism to the core by applying electricity to the coil.

A typical application of electromagnetic induction is a generator, where the basic principle is that a part of a closed circuit is wound into a coil, and then the magnetic inductance line is rotated in a magnetic field to cut the magnetic inductance line, generating an induced current.

A transformer is a device that uses both the magnetic effect of current and the principle of electromagnetic induction. The current passing through the original coil of the transformer will produce an electromagnetic field, and the magnetic effect of the current is used here; The varying magnetic flux in turn induces a current in the secondary coil, where the principle of electromagnetic induction is used.

You see that electromagnetic induction is the principle of generators, so there is no power supply, it is the conductor in the magnetic field to cut the magnetic inductance line movement, and the magnetic effect of the current refers to the existence of a magnetic field around the current, there is a power supply, generally put a small magnetic needle on the side of the energized wire, to see if the small magnetic needle is deflected.

The magnetic effect of electric current is the change in the magnetic field due to the application of electricity, and electromagnetic induction refers to the interaction between electricity and magnetism.

For example, electric stoves and rice cookers use the thermal effect of electric current to work. Electromagnets work using the magnetic effect of electric current. Generators work using electromagnetic induction.

The magnetic effect of electric current is electromagnetism, and electromagnetic induction is magnetism.

The action of the magnetic field on the electric current and the electromagnetic induction, the former is the principle of the electric motor, and the latter is the principle of the generator.

The action of the magnetic field on the electric current and the electromagnetic induction involve three quantities, the direction of the magnetic field, the direction of the current, and the direction of motion, which are perpendicular to each other.

Mutual causality: In a magnetic field, if it moves because of an electric current, it is an electric motor, and if it generates an electric current because it operates, it is a generator. The motor principle uses the left-hand rule, and the generator principle uses the right-hand rule.

The difference in the circuit: there is a power supply in the motor principle circuit, and there is an electrical appliance (galvanometer) in the generator principle circuit, and it is easy to distinguish between them.

As for the magnetic effect of the electric current, it is very simple, there is a magnetic field around the electric current (fact), and the direction of the magnetic field is also determined by the right-hand rule.

There are many ways to heat, the most common is nothing more than an open flame to achieve heat transfer, so do you believe that with a copper wire loop can also achieve the effect of heating?