Final answer:
In AC circuits, the output voltage increases with capacitive loading due to the reduced reactance at high frequencies, optimizing current flow. Transformers with low impedance offer better voltage regulation and may result in high short circuit currents due to limited resistance against the flow of current.
Step-by-step explanation:
Capacitive loading in AC circuits causes an increase in output voltage because, at high frequencies, the reactance of a capacitor (denoted as Xc) decreases. Since reactance is inversely proportional to frequency, a higher frequency results in a lower capacitive reactance, making the capacitor behave like a short circuit. This allows more current to flow and results in a higher output voltage across the load.
Regarding transformers with low impedance, the effects are twofold:
Regulation: Low impedance (small resistance R and reactance X) means that voltage regulation is better since less voltage is lost over the transformer's windings. This ensures that the output voltage remains closer to the ideal or no-load condition, even when the load varies.
Short circuit current: Low impedance would result in a higher short circuit current. This is because, in the event of a short circuit, the only limit to the current flow is the impedance of the transformer's windings. If that impedance is low, the resulting current in a short-circuit situation will be very high, which can be dangerous and requires proper protection mechanisms.