Question

As the frequency of the ac voltage across a capacitor approaches zero, the capacitive reactance of that capacitor:___________.
A) approaches zero.
B) approaches infinity.
C) approaches unity.
D) none of the given answers

Answer 1

Answer:

B) approaches infinity

Explanation:

The capacitive reactance of an AC capacitor is given by;

$X_C = \frac{1}{\omega C } = \frac{1}{2\pi f C}$

Where;

C is the capacitance

f is the frequency of the ac voltage

$X_C = \frac{1}{\omega C} = \frac{1}{2\pi f C} \\\\X_C = \frac{1}{2\pi f C} \\\\X_C = \frac{1}{2\pi (0) C} \\\\X_C = \frac{1}{0} \\\\X_C = \ infinity$

Therefore, as the frequency of the ac voltage across a capacitor approaches zero, the capacitive reactance of that capacitor approaches infinity.

The correct option is (B) approaches infinity