Question

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
• D. The potential difference in the free plates becomes

Answer 1

Answer: (D)

The potential difference in the free plates becomes

Answer 2

$\mathrm { Q } _ { 1 } = \mathrm { CV }$ and $\mathrm { Q } _ { 2 } = \mathrm { CV }$

Applying charge conservation

$C V _ { 1 } + C V _ { 2 } = Q _ { 1 } + Q _ { 2 }$

$C V _ { 1 } + C V _ { 2 } = 2 C V$ ⇒ $V _ { 1 } + V _ { 2 } = 2 V$