# Kirchoff's Current Law

**KIRCHOFF'S LAW**

Many types of circuit have components that are not in series, in parallel or in seriesparalle!. For example, a circuit mav have two voltages applied in different branches. Another example is an unbalanced bridge circuit, where the rules of series and parallel circuit cannot be applied. Hence more general methods of analysis become necessary. These methods include the application of Kirchoff's laws.

**Kirchoff's current Law:**

The algebraic sum of the current entering and leaving any point in a circuit must be equal to zero or the algebraic-sum of currentss into any point of the circuit mustequal the algebraic sum ofthe currents out of that point.

**Algebraic Signs:**

In using Kirchoff's law to solve circuits, it is necessary to adopt conventions that determine the algebraic signs for current and voltage terms. A convenient system for currents is to consider all currents into a branch point as positive and all currents direGled away from that point as negative.

**IA+IB+IC=0**

Current IA and IB is are positive terms because there is current flow into p, but lC directed out, is negative.

see thefigure. there are unknown currents i1, i2 and i3 through the 3 resistors.

we can found These currents using these 3 equations:

1)

2)

3)

Keywords :

Electronic,

Law,

Theory,

Kirchhoff,

Current,

Ohm
**Writer : delon** |

15 Dec 2005 Thr

| 12.120 Views