Node Rule: Difference between revisions

From Physics Book
Jump to navigation Jump to search
Line 11: Line 11:
==Limitations==
==Limitations==
===Time-Varying Currents===
===Time-Varying Currents===
===Maxwell's Equations===
 
Kirchhoff's law is based off the conservation of charge along with the nature of conductors. This law assumes that current will immediately flow from one end of the conductor to the other, which may not be true for time-varying currents, especially with higher frequencies.
 
===Regions vs Circuits===
 
Throughout a region, the charge can vary and be non-uniform, unlike in a wire. According to the law of conservation of charge, the only way to have a non-uniform charge density is if there is a net flow of current in or out of the region, which clearly violates the Node Rule. Therefore the node rule cannot be applied to regions with non-uniform charge densities. When looking at a junction in an electric circuit, we are looking at a point and therefore the point (which is infinitesimally small) must have a uniform charge distribution. In general, wires should have a uniform charge distribution across their length, because they are conductors and allow for the movement of charge.


==Other Topics==
==Other Topics==

Revision as of 16:51, 1 December 2015

claimed by Shannon Gerhard

Definition

The node rule is one of Kirchhoff's laws regarding circuits and current. This law states that at any junction in an electrical circuit, the amount of current flowing into the junction is equal to the amount of current flowing out of the junction. This law is also referred to as Kirchhoff's junction rule, Kirchhoff's nodal rule, Kirchhoff's current law, and Kirchhoff's first law. This rule is an application of the conservation of electric charge, basically that charge within a circuit cannot be created or destroyed.

Mathematically, the Node Rule states ∑ I = 0, where I stands for the current of the individual parts or wires in a circuit.

Kirchhoff's Laws

Limitations

Time-Varying Currents

Kirchhoff's law is based off the conservation of charge along with the nature of conductors. This law assumes that current will immediately flow from one end of the conductor to the other, which may not be true for time-varying currents, especially with higher frequencies.

Regions vs Circuits

Throughout a region, the charge can vary and be non-uniform, unlike in a wire. According to the law of conservation of charge, the only way to have a non-uniform charge density is if there is a net flow of current in or out of the region, which clearly violates the Node Rule. Therefore the node rule cannot be applied to regions with non-uniform charge densities. When looking at a junction in an electric circuit, we are looking at a point and therefore the point (which is infinitesimally small) must have a uniform charge distribution. In general, wires should have a uniform charge distribution across their length, because they are conductors and allow for the movement of charge.

Other Topics

Solving Circuits

History

Put this idea in historical context. Give the reader the Who, What, When, Where, and Why.

See Also

Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?

External Links

https://www.boundless.com/physics/textbooks/boundless-physics-textbook/circuits-and-direct-currents-20/kirchhoff-s-rules-152/the-junction-rule-539-6331/

References

This section contains the the references you used while writing this page