This is a result of the fact that the current, I, in a circuit with series connections is the same in all of the resistors. For more on circuits with resistors in series, please click here .
Voltage is the same across all resistors in parallel.
Therefore, since the voltage is constant, current varies inversely with resistance. A parallel connection implies some kind of branching, where the high potential ends of all the resistors are connected with the low potential ends of all the resistors. For more information on circuits with parallel resistors, please click here . A complex circuit is a branched circuit with multiple voltage sources. The sum of the potentials of all the elements in any closed circuit loop must be zero.