An ac voltage source that has a frequency f is connected across the terminals of a capacitor. Which one of the following statements correctly indicates the effect on the capacitive reactance when the frequency is increased to 4f?
A)The capacitive reactance increases by a factor of four.
B)The capacitive reactance increases by a factor of eight.
C)The capacitive reactance is unchanged.
D)The capacitive reactance decreases by a factor of eight.
E)The capacitive reactance decreases by a factor of four.

Question

Quizplus · Accepted Answer

The capacitive reactance is given by Xc = 1/(2πfC), where f is the frequency and C is the capacitance. When the frequency is increased to 4f, the capacitive reactance decreases by a factor of 4, according to the formula. Therefore, the correct option is E).

An Ac Voltage Source That Has a Frequency F Is