Question

6. Which of the following is blocked by a capacitor ? (A) A.C. (B) D.C. (C) Both A.C. and D.C. (D) Neither A.C. nor D.C ​

Answer 1

Answer:

When the capacitor is connected to the DC voltage source, initially the positive terminal of the DC supply pulls the electrons from one terminal and pushes the electrons to the second terminal. This process continues until one plate is positively charged and the other plate is negatively charged. At this point, the plates of the capacitors are saturated and there will not be any current flow. The capacitor now behaves as an open circuit. Now if the DC voltage is increased the capacitor will get damaged.

Answer 2

Capacitor blocks (B) D.C.

Explanation:

• Alternating current has different polarities. A capacitor connected to alternating current voltage source, gets charged initially but as soon as the direction of alternating current is changed, the capacitor gets discharged.
• When a capacitor is connected to a direct current voltage source, a very small amount of charge flows through the capacitor but then it gets blocked.
• Capacitors act as short circuit to DC voltage.
• In case of direct current connected to capacitor, the capacitor gets charged fast and then halts further passing of current through it.
• In case of alternating current connected to capacitor, the capacitor gets charged discharged continuously which causes continuation of current flow.