In capacitive reactance, increasing frequency (f) will have what effect on Xc?

• A. Xc increases
• B. Xc decreases
• C. Xc remains unchanged
• D. Xc becomes negative

Answer: (B)

Capacitive reactance (Xc) is a measure of how much a capacitor resists the flow of alternating current (AC) and is calculated using the formula:

[ Xc = \frac{1}{2\pi f C} ]

In this formula, (f) represents the frequency of the AC signal, and (C) represents the capacitance of the capacitor.

As frequency increases, one can observe that the denominator of the equation increases due to the (f) term. Since (Xc) is inversely related to frequency, an increase in frequency will lead to a decrease in capacitive reactance. Thus, when frequency rises, the capacitive reactance decreases, allowing more AC current to flow through the capacitor.

This inverse relationship indicates that at higher frequencies, capacitors allow more current to pass, which is an important concept in AC circuit analysis.