When an uncharged capacitor is connected to a dc source, which of the following happens?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → The current flows at first and falls to zero as the capacitor gets charged.
Option (1) No current flows, as a capacitor offers infinite resistance to a dc source. — Incorrect. Charge does flow onto the plates while the capacitor charges, so a current flows for a short time. The current becomes zero only after charging is complete.
Option (2) The current flows without any hindrance. — Incorrect. As charge builds up, the voltage across the plates rises and opposes the source, so the capacitor limits the current as it charges.
Option (3) The current flows at first and falls to zero as the capacitor gets charged. — Correct. On connection, a current flows for the short time needed to charge the capacitor. The rising voltage across the plates opposes this current. When the capacitor is fully charged, its voltage equals the source voltage and the current falls to zero.
Option (4) The current is hindered at first and later flows smoothly. — Incorrect. The current is largest just after connection and is reduced as the capacitor charges. Once it is fully charged, no steady current flows.
NCERT (2026-27):
AC Voltage Applied to a Capacitor – “When a capacitor is connected to a voltage source in a dc circuit, current will flow for the short time required to charge the capacitor. As charge accumulates on the capacitor plates, the voltage across them increases, opposing the current. That is, a capacitor in a dc circuit will limit or oppose the current as it charges. When the capacitor is fully charged, the current in the circuit falls to zero.”