Question

Как можно объяснить закон Джоуля-Ленца на основании электронной теории?

Answer 1

На основании классической электронной теории проводимости металлов можно объяснить закон Джоуля-Ленца.

Упорядоченное движение электронов происходит под действием сил поля. Как и выше, будем считать, что в момент соударения с положительными ионами кристаллической решётки электроны полностью передают ей свою кинетическую энергию.

Answer 2

Explaining the Joule-Lenz Law Based on the Electronic Theory

The Joule-Lenz law, also known as Lenz's law, is a fundamental law in electromagnetism that describes the direction of induced electromotive force (emf) and current resulting from electromagnetic induction. This law is based on the electronic theory and can be explained as follows:

1. Electromagnetic Induction: - According to the electronic theory, when a conductor is exposed to a changing magnetic field, an electromotive force (emf) is induced in the conductor, resulting in the generation of an electric current. This phenomenon is known as electromagnetic induction.

2. Direction of Induced Current: - Lenz's law states that the direction of the induced current is such that it opposes the change in magnetic flux that produced it. In other words, the induced current creates a magnetic field that opposes the change in the original magnetic field.

3. Conservation of Energy: - This phenomenon is in accordance with the principle of conservation of energy, as the induced current and resulting magnetic field work against the change in the original magnetic field, thereby dissipating energy in the form of heat within the conductor.

4. Mathematical Representation: - Mathematically, Lenz's law can be expressed as the negative sign in Faraday's law of electromagnetic induction, which states that the induced emf in a closed loop is equal to the negative rate of change of magnetic flux through the loop.

5. Practical Applications: - Lenz's law has practical applications in various electromechanical devices, such as generators, transformers, and inductors, where it governs the direction of induced currents and the resulting magnetic fields.

In summary, the Joule-Lenz law, based on the electronic theory, explains the direction of induced current and electromotive force in a conductor in response to a changing magnetic field, with the induced current opposing the change in the original magnetic field to conserve energy.