A capacitor consists of two conducting plates separated by an insulating medium. It can store electric charges, in the form of voltage in electric field. That blocks direct current. This opposes any sudden change of voltage applied to it. That only allows the Alternating current. That makes the time delay
C=Ԑ o Ԑr A / d farad A=area of each plate in m2,
- d=distance between the plates in meter, Ԑr =relative dielectric constant(permittivity).
- Ԑ o=dielectric constant(permittivity)of free space,