MCQ
Two identical capacitors are joined in parallel, charged to a potential $V$ and then separated and then connected in series $i.e.$ the positive plate of one is connected to negative of the other
  • A
    The charges on the free plates connected together are destroyed
  • B
    The charges on the free plates are enhanced
  • C
    The energy stored in the system increases
  • The potential difference in the free plates becomes $2\,V$

Answer

Correct option: D.
The potential difference in the free plates becomes $2\,V$
d
(d) ${Q_1} = CV$ and ${Q_2} = CV$
Applying charge conservation $C{V_1} + C{V_2} = {Q_1} + {Q_2}$
$C{V_1} + C{V_2} = 2CV$ $==>$ ${V_1} + {V_2} = 2\,V$

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