Question

Why does a capacitor works On Alternating Current only?

Answer 1

As we know the formula for capacitative reactance is
Xc = 1/2πvC

For d.c. v(nu) = 0

so Xc = ∞

i.e. a capacitor will provide infinite resistance to DC and thus will block it.

That is why a capacitor only works on AC


hope it helped