Kirchhoff’s First Law



Kirchhoff’s First Law states that the total current entering a junction is equal to the total current leaving the junction. OR The algebraic sum of currents at a junction is zero.

Kirchoff current rule
 

Referring to the diagram above, the current entering any junction is equal to the current leaving that junction. Hence, i1 + i4 = i2 + i3

Kirchhoff’s first law is a statement of the conservation of charges.

  • Whatever current enters a given junction in a circuit must leave that junction since charge cannot be created or destroyed at a junction.
  • Charge cannot escape from the wire but has to flow around the circuit.

Video of the Kirchhoff’s First Law. The ‘i’ in the video is current. (Not a complex number)


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