Which device provides capacitive reactance in a circuit?

Which device provides capacitive reactance in a circuit?

• A. Resistor
• B. Inductor
• C. Capacitor
• D. Transformer

Answer: (C)

Capacitive reactance comes from the capacitor’s ability to store and release charge in an AC circuit, which opposes the current flow. This opposition is described by Xc = 1/(2πfC): it decreases as frequency or capacitance increases. In DC, a capacitor blocks current once charged, acting like an open circuit, while in AC it presents this reactive opposition. Resistors don’t create reactance; they offer pure resistance with no phase shift. Inductors create inductive reactance, causing current to lag voltage. A transformer isn’t a source of capacitive reactance by itself, since it relies on inductive effects.

Capacitive reactance comes from the capacitor’s ability to store and release charge in an AC circuit, which opposes the current flow. This opposition is described by Xc = 1/(2πfC): it decreases as frequency or capacitance increases. In DC, a capacitor blocks current once charged, acting like an open circuit, while in AC it presents this reactive opposition. Resistors don’t create reactance; they offer pure resistance with no phase shift. Inductors create inductive reactance, causing current to lag voltage. A transformer isn’t a source of capacitive reactance by itself, since it relies on inductive effects.