# Kirchhoff's Laws

Written by Jerry Ratzlaff on . Posted in Electromagnetism

## Kirchhoff's Current Law

Kirchhoff's first law, abbreviated as KCL, says the sum of all currents that enter or leave a junction or node equals 0.   Or you could say the current going into is equal to the current going out of a junction or node.

• $$\large{ I_a - I_b =0 }$$
• $$\large{I_a + I_b + I_c - I_d - I_e = 0 }$$

## Kirchhoff's Voltage Law

Kirchhoff's second law, abbreviated as KVL, says the sum of all voltages in an circuit loop is 0.

• $$\large{V_a - V_b = 0 }$$
• $$\large{V_a + V_b + V_c - V_d - V_e = 0 }$$