Steps for Applying Kirchhoff Rules
- Draw the circuit, label all the known and unknown quantities.
- Assign a direction to the currents in each part of the
- If you guess the direction of the current incorrectly, your
result will be negative. However, the magnitude will be the
- You must adhere to the assigned direction.
- Apply the junction rule to any junction in the circuit.
- Apply the second rule to as many loops in the circuit as
- Choose a loop and a starting point ( arbitrary ).
- Choose a direction ( clockwise or counter-clockwise ) and
traverse the loop.
- If a resistor is traversed in the direction of the
current : the change in the 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 – e .
- If an emf is traversed from the – to the + terminal
: the change in potential is + e.
- Solve the equations simultaneously for the unknown quantities.