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Chapter 26

Current and Resistance

Prąd elektryczny
Prąd elektryczny
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 ...
Prędkość dryfu
Prędkość dryfu
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 ...
Gęstość prądu
Gęstość prądu
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, ...
Rezystywności
Rezystywności
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 ...
Opór
Opór
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 ...
Prawo Ohma
Prawo Ohma
Many materials exhibit a simple relationship between the values of current, voltage, and resistance, known as Ohm’s law. The current that flows ...
Urządzenia nieomowe
Urządzenia nieomowe
In most substances, the current flow is proportional to the voltage applied to it. A simple relationship between the values of current, voltage, and ...
Energia elektryczna
Energia elektryczna
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 ...
Energia elektryczna
Energia elektryczna
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 ...
Równanie ciągłości
Równanie ciągłości
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 ...
Warunki brzegowe dla gęstości prądu
Warunki brzegowe dla gęstości prądu
Current density becomes discontinuous across an interface of materials with different electrical conductivities. The normal component of the current ...
Przewodnictwo
Przewodnictwo
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, ...
Teoria przewodnictwa metalicznego
Teoria przewodnictwa metalicznego
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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