Question

A capacitors is charged to store an energy $U$. The charging battery is disconnected. An identical capacitor is now connected to the first capacitor in parallel. The energy in each of the capacitors is

• A. $\frac{U}{2}$
• B. $\frac{3U}{2}$
• C. $U$
• D. $\frac{U}{4}$

Answer 1

Answer: (A)

$\frac{U}{2}$

After the battery is disconnected, we have conservation of charge and also energy is equal to $\frac{q^2}{2\times C}$ i.e $\frac{U}{2}$
So the answer comes as $\frac{U}{2}.$