Norton’s theorem

Norton’s theorem

steps

1. Short the branch through which the current is to be calculated
2. Find  out the current through this short circuited branch. This current is nothing but norton’s current IN
3. Calculate the equivalent impedance Zeq as  viewed through the two  terminals of  interest by removing the branch impedance and moving all the independent sources inactive.
4. The current through the branch of interest  is
5.                
6.      I= IN ×(Zeq /(Zeq +ZL))
7.