Question

Two identical capacitors are connected in parallel across a potential difference $V$. After they are fully charged, the positive plate of first capacitor is connected to negative plate of second and negative plate of first connected to positive pate of other. The loss of energy will be

• A. $\frac{1}{2}C{V}^2$
• B. $C{V}^2$
• C. $\frac{1}{4}C{V}^2$
• D. $Zero$

Answer 1

The correct option is B $C{V}^2$

$\Delta U=\frac{1}{2}\frac{C_1{C}_2}{C_1+C_2}(V_1-V_2{)}^2$

$=\frac{1}{2}\frac{C^2}{2C}(V-(-V){)}^2$

$\therefore \Delta U=C{V}^2$