## Kirchohoff low

**
Kirchhoff's
Current Law
At any instant the sum of all the currents flowing into any circuit node is
equal to the sum of all the currents flowing out of that node:
SI_{in}
= SI_{out} **

**
Similarly, at any instant the
algebraic sum of all the currents at any circuit node is zero:
SI = 0
**

Kirchhoff's Voltage Law

At any instant the sum of all the voltage sources in any closed circuit is
equal to the sum of all the voltage drops in that circuit:

SE =
SIZ

Similarly, at any instant the algebraic sum of all the voltages around
any closed circuit is zero:

SE -
SIZ = 0