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Additional Formulas

· Coulomb's Law
· Gauss' Law
· Application of Gauss’s Theorem
· Joule's Law
· Kirchhoff's Current Law
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· Wave
· Refraction and Reflection
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Current Location > Physics Formulas > Electromagnetism > Kirchhoff's Current Law

Kirchhoff's Current Law

The total current flow into a surface is positive, therefore the current flow outside or leaving the surface must be minus, therefore the current leaving the surface can be written as:

The current leaving the source is the total outward flux of the current density vector through surface S. Using divergence theorem we have:

For a steady current the current density does not vary with the time, therefore

, and we have:

and