Steps for
applying Kirchhoff rules
1.
Draw the circuit; label all the known
and unknown quantities.
2.
Assign a direction to the currents in
each part of the circuit:

If you guess the direction of the
current incorrectly, your result will be negative. However, the magnitude will
be correct.

You must adhere to the assigned
direction.
3.
Apply the junction rule to any
junction in the circuit.
4.
Apply the second rule to as many
loops in the circuit as needed:

Choose a direction (clockwise or
counterclockwise).

If a resistor is traversed in the
direction of the current: the change in potential is – I
R.

If a resistor is traversed opposite
to the direction of the current: the change in potential is + I
R.

If an emf
is traversed from the + to the – terminal: The change in potential is 
_{}.

If an emf
is traversed from the  to the + terminal: The change in potential is + _{}.
5. Solve the equations simultaneously
for the unknown quantities.