Final answer:
True, DC circuits normally have no lead or lag in current vs. voltage, because in a pure resistive DC circuit, voltage and current are in step once a steady state is achieved.
Step-by-step explanation:
The statement 'DC circuits have no lead or lag in current versus voltage' is generally true. In a pure DC circuit, where only resistive components are present, voltage and current are in step with each other as Ohm's law dictates. When the circuit reaches a steady state, the voltage across and the current through a resistor are constant over time. Hence, in resistive DC circuits, there's no phase difference; the voltage does not lead or lag the current. This means that the values of voltage and current do not change with time once the current is established, unlike in an AC circuit where they can fluctuate and be out of phase depending on the circuit components involved like inductors and capacitors.
However, if inductive or capacitive elements were introduced into a DC circuit, there might be a temporary lead or lag during the transient period when the circuit is changing states, but this is not characteristic of an established, steady-state DC circuit.