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 above.

Answer 1

b. approaches infinity

Step-by-step explanation:

Because Capacitive reactance is given as Xc = 1/ωC

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So we can see that the value of capacitive reactance and therefore its overall impedance (in Ohms) decreases to zero as the frequency increases acting like a short circuit.

Same as the frequency approaches zero or DC, the capacitors reactance increases to infinity, acting like an open circuit which is why capacitors block DC