(3)

Step 1:

Find the current passing through the branch which have the resistance $\"\"$ and voltage $\"\"$ .

(From the results of http://www.mathskey.com/question2answer/31774/norton-equivalent-circuit

Nortons Resistance is

\"\"

Nortons Current is

\"\"

Redraw the circuit :

$\"\"$

Use the Current Division Rule to find current across $\"\"$ .

$\"\"$

Substitute corresponding values in $\"\"$ .

$\"\"$

Step 2:

Convert the voltage source into current source using source transformation.

$\"\"$ .

Substitute $\"\"$ and $\"\"$ .

$\"\"$

Current passing through the branch : $\"\"$ .

Substitute $\"\"$ and $\"\"$ in $\"\"$ .

$\"\"$

Current passing through the branch is $\"\"$ .

Solution :

Current passing through the branch is $\"\"$ .