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Kapitel 26

Current and Resistance

Elektrischer Strom
Elektrischer Strom
Electrical current is defined as the rate at which charge flows. When there is a large current present, such as that used to run a refrigerator, a large ...
Drift-Geschwindigkeit
Drift-Geschwindigkeit
The high speed of electrical signals results from the fact that the force between charges acts rapidly at a distance. Thus, when a free charge is forced ...
Stromdichte
Stromdichte
The total amount of current flowing through one unit value of a cross-sectional area is referred to as current density. If the current flow is uniform, ...
Widerstandsgröße
Widerstandsgröße
When a voltage is applied to a conductor, an electrical field is generated, and charges in the conductor feel the force due to the electrical field. The ...
Widerstand
Widerstand
When a current moves through any conductor, the conductor causes some level of difficulty for the current to flow. The measure of that difficulty is known ...
Das Ohmsche Gesetz
Das Ohmsche Gesetz
Many materials exhibit a simple relationship between the values of current, voltage, and resistance, known as Ohm’s law. The current that flows ...
Nicht-ohmsche Bauelemente
Nicht-ohmsche Bauelemente
In most substances, the current flow is proportional to the voltage applied to it. A simple relationship between the values of current, voltage, and ...
Elektrische Leistung
Elektrische Leistung
Electric power is the product of current and voltage, represented in units of joules per second, or watts. For example, cars often have one or more ...
Elektrische Energie
Elektrische Energie
Using electric appliances for a longer period of time consumes more electrical energy and results in a higher electric bill. The energy produced by the ...
Kontinuitätsgleichung
Kontinuitätsgleichung
The total amount of current flowing per unit cross-sectional area is called the current density. Hence, the current passing through a cross-sectional area ...
Randbedingungen für die Stromdichte
Randbedingungen für die Stromdichte
Current density becomes discontinuous across an interface of materials with different electrical conductivities. The normal component of the current ...
Elektrische Leitfähigkeit
Elektrische Leitfähigkeit
In perfect conductors, the electric field inside is always zero due to the abundance of free electrons, which nullify any field by flowing. As a result, ...
Theorie der metallischen Leitung
Theorie der metallischen Leitung
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the ...
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