What is called induction current: EMF formula, principles of occurrence and conducting experiments

Electromagnetic induction refers to the phenomenon when an electric current, field or polarization occurs. In this case, there is a change in the time interval for the magnetic field or the movement of the material medium inside the latter. The founder of electromagnetic induction is Michael Faraday. He conducted numerous studies to determine what current is called induction.

Basic Provisions

Michael Faraday made this discovery by experiment. He proved that magnetic flux tends to change. When oscillations occur, an electromotive force appears. Its speed is equal to the movement of the magnetic flux, which passes through the entire surface of the contour.

This pattern has received the official name - Faraday's law or magnetic induction. Experience clearly shows that induction electric current occurs exclusively in a closed circle when variations in magnetic flux occur.

To obtain the formula for the induction current, it is necessary to divide the value of the electromotive force acting along an arbitrary contour by the magnetic flux.

The current tends to move across the entire surface, and also limited to a certain contour. The formula is preceded by the sign "la-la", which reflects the rule of Lenz, a Russian physicist who also studied induction. Through research, experimentation and experimentation, he created his own rule. The induction current arising inside a closed conducting loop has a certain direction. In this case, the magnetic field helps to counteract the change in flux.

Thanks to the formula, it is possible to determine the EMF of electromagnetic induction, which moves along the field contour in an arbitrary form, the level of resistance and self-induction.

The importance of induction in electrical engineering

Thanks to this law, other scientists began to develop new electrical equipment. They received electricity through the action of a magnetic field. The law of electromagnetic induction is the opposite process. With it, mechanical energy is converted into an electric field force.

Today, during the production of electrical devices, the principle of electromagnetic induction is applied. Thanks to this scheme, various electrical machines are made. The phenomenon of magnetic induction and strength depends on the line that is in the field. It crosses the conductor in one unit of time. When the action of the electromotive force increases, then it crosses the magnetic field.

Design features

To understand the formula and principle of action, you need to study what current is called induction. It begins to arise during a change in the flux of magnetic induction in a conductive circuit. To determine the direction, you need to use the Lenz rule.

When the flow changes, the loop begins to compensate for these changes. If the field is created in another contour, the direction begins to change. There is an increase in the external flow, therefore the induction current reverses direction.

The coils have two main poles - north and south. The pole is determined depending on the current direction of the current. Sometimes induction lines can come out of the North Pole. When the magnet gradually approaches the coil, the phenomenon of magnetic induction occurs with the principle of repulsion.

Induction current appears only if there is a closed loop that is located in an alternating magnetic field. The contour can be stationary or moving. There are several ways to create inductive current:

• moving the permanent magnet relative to the coil;
• changing the position of the core (it is mounted in the coil of an electric magnet);
• opening and closing a circuit;
• level regulation.

Thanks to modern technologies using induction, manufacturers make home appliances. These can be boilers and stoves.

Faraday's experiments at home

For a more accurate understanding of the origin and phenomenon of electromagnetic induction, several experiments can be carried out. They are performed at home or in physics classrooms. Here are the most common and available ones:

1. A conductor can be connected to the galvanometer. It should be long and flexible. It is placed between the different poles of the magnet. When the conductor and magnet are stationary, there is no current. If it starts to move, then there is tension in the circuit. The galvanometer needle will deviate in different directions.
2. Connect the coil to the galvanometer. A magnet can be inserted or exited inside the field. The galvanometer will record the appearance of current in the closed circuit of the circuit.
3. Fasten the magnet in the tripod, put on the coil, attach to the galvanometer. The current will reappear in the coil, but only if there is movement.

These experiments should be done with a teacher or adults who can correctly make all the necessary connections. It is important to go through safety precautions before starting to avoid mistakes.