Final answer:
In AC circuits with only resistive elements, all DC rules and laws including Ohm's law apply, with equations being analogous but using rms and average values instead of peak values. Instruments like voltmeters and ammeters measure these rms values in AC circuits, which correspond to DC values in resistive circuits.
Step-by-step explanation:
All DC rules and laws including Ohm's law apply in AC circuits containing only resistive elements because there are no reactive components (capacitors or inductors) to cause phase shifts between current and voltage. Therefore, when the circuit is purely resistive, DC and AC equations are analogous. However, it is important to consider the root-mean-square (rms) and average values when dealing with AC circuits. For example, Ohm's law for AC circuits is expressed using rms values, allowing for straightforward comparisons between AC and DC in terms of resistance, voltage, and current.
In the context of AC circuits, Kirchhoff's laws, which include both Kirchhoff's voltage law and Kirchhoff's current law, are also applicable, just as they are in DC circuits. Instruments such as voltmeters and ammeters are used to measure the voltage and current, respectively. When using these instruments in AC circuits, they measure the rms values which correspond to the equivalent DC values a resistive circuit would have.
It's also important to note that it is not possible to produce nonzero DC current by adding together AC currents because AC currents vary with time and, when combined, will still result in a current that varies with time, rather than a constant DC current.