Question 437: AC fundamentals

Question

An ac source is connected to a capacitor C. Due to decrease in its operating frequency

Accepted Answer

When an AC source is connected to a capacitor, the current (I) depends on the capacitive reactance (X
C
), where $$X_{C} = \frac{1}{\omega C}$$, with $\omega$ representing the angular frequency $\omega = 2\pi f$, and C denoting the capacitance.
The formula for capacitive reactance shows that it is inversely proportional to the frequency (f) of the operation.
Thus, if the frequency decreases, the capacitive reactance increases because $X_{C} = \frac{1}{\omega C}$ and $\omega$ is proportional to frequency.
As capacitive reactance increases, the displacement current (I), which flows through the capacitor, decreases according to the relationship $$I = \frac{V}{X_{C}}$$, with V being the voltage across the capacitor.
So, among the given choices, the correct interpretation is that the displacement current decreases with a decrease in operating frequency.

Answer

displacement current increases.

Answer

displacement current decreases.

Answer

capacitive reactance remains constant.

Answer

capacitive reactance decreases.

AC fundamentals

An ac source is connected to a capacitor C. Due to decrease in its operating frequency

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