Which phenomenon best describes the effect of frequency on capacitor reactance?

Which phenomenon best describes the effect of frequency on capacitor reactance?

• A. XC increases with frequency
• B. XC ends with frequency
• C. XC decreases with frequency
• D. XC is unaffected by frequency

Answer: (C)

The correct answer highlights that capacitive reactance, denoted as XC, decreases with increasing frequency. This relationship is a fundamental aspect of how capacitors function in alternating current (AC) circuits. As the frequency of the AC signal increases, the reactance of the capacitor, which can be calculated using the formula XC = 1/(2πfC), demonstrates that the reactance is inversely proportional to both the frequency (f) and the capacitance (C). This means that at higher frequencies, the denominator becomes larger, resulting in a smaller value for XC. In practical terms, this indicates that a capacitor will allow more AC current to pass through as the frequency increases, making capacitors useful for filtering and timing applications in electronic circuits. In scenarios where capacitors are used for coupling or decoupling AC signals, lower reactance at higher frequencies ensures better signal integrity and efficiency in transmission. Understanding this relationship is crucial for effectively working with AC circuits in HVAC systems, where capacitors play significant roles in various components, such as motors and control systems.

The correct answer highlights that capacitive reactance, denoted as XC, decreases with increasing frequency. This relationship is a fundamental aspect of how capacitors function in alternating current (AC) circuits.

As the frequency of the AC signal increases, the reactance of the capacitor, which can be calculated using the formula XC = 1/(2πfC), demonstrates that the reactance is inversely proportional to both the frequency (f) and the capacitance (C). This means that at higher frequencies, the denominator becomes larger, resulting in a smaller value for XC.

In practical terms, this indicates that a capacitor will allow more AC current to pass through as the frequency increases, making capacitors useful for filtering and timing applications in electronic circuits. In scenarios where capacitors are used for coupling or decoupling AC signals, lower reactance at higher frequencies ensures better signal integrity and efficiency in transmission. Understanding this relationship is crucial for effectively working with AC circuits in HVAC systems, where capacitors play significant roles in various components, such as motors and control systems.