As we know that Ohm’s
law can be applied to circuits where there are resistive circuits only. Now in electrical systems there are so many
complex circuits consisting of lot of other load other than resistive loads. There
are some circuits such as Bridge circuits which can’t be solved by using ohm’s
law to find out voltages and currents circulating in the circuit. Kirchoff’s
current law is used to solve the circuits to find out the current flowing the
respective branches.

Kirchoff’s current law
was given by Gustav Kirchoff in 1845. There are two laws given by Kirchoff
naming as Kirchoff’s current law and Kirchoff’s voltage laws. KCL deals with
current flowing in a closed circuit whereas KVL deals with voltage sources
present in a closed circuit.

**Kirchoff’s Current Law:-**

According to this law “Total
current entering a Junction or node is equal to current leaving the same
junction or node”. This means that algebraic
sum of currents entering and leaving the junction or node is always zero. Currents
entering the particular node are represented by positive and currents leaving
the junction or node are presented as negative.

Kirchoff’s current law
is also knows as Conservation of charges.

In Figure below you will
see that at a particular Junction or node; Sum of currents entering the node=
Sum of currents leaving the node

In figure you will see
that:-

I1+ I2+ I3= I4+I5+ I6

Kirchoff’s current law
can be used for analysis of parallel circuits.

**Kirchoff’s Voltage Law:-**

According to this law “in a closed network the total voltage around the
closed circuit is equal to sum of voltage drops within the same circuit.”

This means that algebraic sum of all
voltages within the closed circuit is always equal to zero. This law is also
known as Conservation of Energy.

In figure below you
will see that in a closed loop there is direction of voltage drop is positive
at point V12 and V23 but –ve in V34 and V41. So sum of all voltages in circuit
is zero. It should be kept in mind that direction should be either selected as
clockwise or anticlockwise for whole circuit.

Kirchoff’s voltage law
is used to analyze Series circuit.

Kirchhoff's rules can be used to analyze any
circuit this can be modified for those with EMFs, resistors, capacitors and more

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