Three identical parallel plate capacitors are connected in parallel to a 2 volt battery. The battery is disconnected and the three capacitors are joined in series. What is the potential difference between X and Y?

6 V

The correct answer is Option (3) → 6 V

Voltage Across each capacitance = $QV$

When they are connected in parallel

∴ Voltage when they are connected in series = $3 × 2 = 6V$