question_answer 50)

  Explain why the reactance provided by a capacitor to an alternating current decreases with increasing frequency.

Answer:

                  A capacitor does not allow the flow of direct current through it as resistance across the gap between the two plates is infinite. When an alternating voltage is applied across the capacitor plates, the plates are charged and discharged alternately. Current through capacitor is as a result of this changing voltage (or charges). Current will be more when voltage changes at a faster rate, i.e., reactance offered by condenser will be smaller when frequency of voltage changes is increased. Mathematically,