KVL is derived from the fact that the voltage at any point in the circuit must have one single value. For example, say you start at point A and travel around the loop adding up voltages along the way. If the voltage drops did not sum to zero, then when you returned to point A it would have a different voltage than when you started, which is impossible.<ref name="Schwarz" /> | KVL is derived from the fact that the voltage at any point in the circuit must have one single value. For example, say you start at point A and travel around the loop adding up voltages along the way. If the voltage drops did not sum to zero, then when you returned to point A it would have a different voltage than when you started, which is impossible.<ref name="Schwarz" /> |